the president says the wall would stop illegal immigrants, but democrats claim his national emergency is a gross abuse of power. we'll have a special report from our correspondent on the border between california and mexico. after spending time here, it would be easy to question the president's rhetoric, his talk of a crisis, and the threat these people pose, how simple he makes a wall sound as a solution, but it's clear there is a complex game of cat—and—mouse being played here. also this lunchtime... the teenager whojoined islamic state — the home secretary says he'll try to stop her coming back to britain. how books sprayed with drugs are smuggled into one of britain's most troubled jails. school's out! thousands of pupils go on strike in protest against government thousands of pupils go on strike

in protest against climate change. newsreel: the arrivals of children. the empire windrush. and the author who chronicled the windrush generation, andrea levy, has died at the age of 62. and coming up on bbc news... maurizio sarri says consistency is now the key for chelsea after they responded to a 6—0 drubbing with a europa league win in sweden. good afternoon and welcome to the bbc news at one. president trump is invoking emergency powers to pay for his border wall with mexico. it's a rare and controversial move — and it would bypass congress, which has so far refused to approve the money he needs for the wall,

one of his key campaign promises. senior democrats have accused mr trump of a gross abuse of power and a "lawless act", and some of his own republican party are also uneasy. from washington, chris buckler reports. we're going to have our borders nice and strong, we're going to build the wall... going to build a wall... we have to build a wall, folks. the long border that divides the us and mexico is at the centre of america's own political divide. building a huge barrier here has become more than a priority for president trump, it's become a point of principle. yet after all his threats that he wouldn't accept any funding bill that didn't include more than $5 billion for his long—promised wall, he's had to accept a congressional compromise. the ayes are 300, the nayes are 128. after all the talk, the legislation passed with little controversy or opposition. republicans were clearly relieved to avoid another government shutdown,

but they know this fight isn't over. i've just had an opportunity to speak with president trump and he, i would say to all my colleagues, has indicated that he's prepared to sign the bill. he will also be issuing a national emergency declaration at the same time. today, we started a big, beautiful wall right on the rio grande... cheering. this week, president trump held a rally beside the border in texas, where he again made a pledge to supporters that he would build the wall. declaring a national emergency could allow him to use money from other funds, but his plan is likely to face challenges in court. did i would say i was filing a legal challenge? you said democrats... i may, that's an option, and we'll review our options. but it's important to note that when the president declares this emergency, first of all, it's not an emergency... what do we want...?! the trump administrations administration policies have the trump administration's

immigration policies have led to many protests, and many americans will be looking to see where the president tries to find the billions of dollars he needs. it's thought he's looking at military budgets and perhaps even disaster relief funds. mr trump once promised mexico would pay for the wall. then he turned to congress. now, he's relying on his own presidential powers. but in building physical barriers, he knows he faces political ones. chris buckler, bbc news, washington. so, what is the reality of what's happening on the us border at the moment? well, in recent months, fences have been strengthened, but more people are still trying to cross illegally every week. there are some flashing images in this report from our correspondent dan johnson, who's on the border between mexico and california near san diego. after 2,500 miles, these are the final few steps. this is journey‘s end. whoa, whoa, whoa! where the fence runs out, this mother and her daughter fall into the arms of us border patrol.

my little girl is hungry, she says, and i don't have any money. and there are over 1000 more who cross illegally everyday. they speak spanish. a crisis, the president says, that stretches from the hills all the way to the sea. it's not climbing over a fence or digging under a fence or taking a dangerous smuggling boat up the coast, it's presenting yourself at a port of entry, that's a secure border. they say more fence frees up more agents to deal with the queues at crossings. 0nly limited numbers are currently allowed through to claim asylum. there's already a fence of one kind or another along a third of the 2,000—mile border. 18ft, steel slatted, concrete filled barrier, with anticlimb plates on top.

here, it's already being upgraded and it's making a difference. this barrier takes significantly more time to penetrate, to cut through. it takes ten, 20, up to 30 minutes, depending on the type of blade that you're using. this border barrier can be compromised in about a minute and 20 seconds. before this barrier went into place, this happened every single night. every single night this fence was cut or breached or compromised. so, the chief here shares the president's ambition to extend this fence across these hills. we have to have a barrier or we will never win that time distance game. the smugglers are using those people that are trying to claim asylum as a distraction to overload my resources so they can run drugs in other areas. that's a huge threat, and there's a humanitarian crisis and there's a national security crisis and they're butting up against each other. but the numbers are way down, aren't they? you look back ten, 20, 30 years, the problem you're dealing with today is nothing like it was? i wouldn't say it's nothing like it was, i would say that it's changed but that again it's

the equivalent of saying, if your house is only getting robbed one day out of the week instead of all seven, that you're done. we're not done. of all the forces at work here, inequality‘s push and pull is the most stubborn. these families will keep coming as long as they see greater security and prosperity. she speaks spanish. i'm escaping guatemala, she says, because there are many robberies, children are kidnapped, there's lots of crime and the police do nothing. it could take years to determine their future because the system is so backlogged. after spending time here, it would be easy to question the president's rhetoric, his talk of a crisis and the threat these people pose, how simple makes a wall stand sound these people pose, how simple makes a wall sound as a solution. but it's clear there is a complex game of cat and mouse being played here,

and the border patrol agents say it is unsustainable. for them and for the people trying to cross. manpower, horsepower, all of it is stretched. this deal ends government gridlock for now but securing this dividing line has become the defining issue of donald trump's presidency. and even with emergency funding, this fence won't go as far as he'd like. danjohnson, bbc news, san diego. 0ur correspondent gary 0'donoghue is in washington. so, we're expecting to hear from president trump in the next couple of hours, what is he likely to say? well, idea expecting him to announced that he's going to sign that spending bill to start with that spending bill to start with that congress has passed through both houses of. that would give him something like $1.37 billion towards the $5.7 billion he said he needs for border security, including about 50—odd miles of wall. but we are also expecting him to announce a national emergency, and that would allow to go looking, at least for

the time being, for other money. and we think he's going to go looking for about another $7 billion from things like the defence budget and things like the defence budget and things like the defence budget and things like emergency aid budgets for victims of hurricane spot, floods and drug enforcement programs. now, that will be something that many in congress will be very unhappy about, congress controls the money in this country any raising of it and the spending of it, so he is likely to face a number of legal challenges, even congressional votes, and there are some in his own party who are not happy about it at all. but it's important for him to prove to his supporters that this signature, key policy is still on track. the home secretary sajid javid has indicated he is prepared to stop a teenager whojoined the islamic state group from coming back to britain. shamima begum travelled to syria four years ago when she was 15, but has now said she wants to return to the uk to raise her unborn child. the home secretary has said

he won't let anything jeopardise britain's safety and security. 0ur correspondent richard galpin is at the home office. richard, what are the government's options? well, it seems that there is a series of options which the home 0ffice series of options which the home office here could start looking at. 0ne office here could start looking at. one is simply to cancel her passport. another perhaps more controversial is to strip her of her nationality as a british citizen. and also there's a possibility of a temporary ban on her coming into the uk and during that time she would then have to agree to be investigated by the british authorities and monitored and go into a authorities and monitored and go intoa d authorities and monitored and go into a d radicalised program. so that would have to be all done outside britain before she could then come back in. but i think for short, ben, if she does come back

into the uk, she will be investigated by the police and could face possible charges of breaching terrorism laws. in another development today, at a security conference in munich to head of m16 has been speaking and he's been saying that he is deeply concerned about jihadists saying that he is deeply concerned aboutjihadists returning saying that he is deeply concerned about jihadists returning to saying that he is deeply concerned aboutjihadists returning to europe and he is also concerned about the fa ct and he is also concerned about the fact that the islamic state group and al-qaeda are now regrouping rahman the massive military defeats which they have suffered in recent yea rs. which they have suffered in recent years. richard galpin, thank you very much, at the home office. the prisons minister says there are early signs that violence in ten of england's worst prisons is reducing. last august, rory stewart said he'd resign if there weren't improvements within a year. but mr stewart has also warned some prisons continue to cause serious concern. inmates at nottingham, for example, are suspected to have smoked the pages of a book that had been sprayed with drugs and smuggled inside. our home affairs correspondent danny shaw has had special

access to the jail. 0k, guys, we're going to do a routine cell search this afternoon. the value of experience. these senior prison officers have been brought in to hmp nottingham to guide newer members of staff. more than half of those working here have less than two years' service. they need help to carry out basic duties, like searching cells for drugs and weapons. pay attention to slits like that. you can't prepare for a job like this, the noise, the smell. when you come into contact with somebody that is threatening to take their own life or attempting to take their own life, that's probably the scariest most daunting situation i've found myself in, and to have that experience there, to reassure me and the prisoner was really beneficial. nottingham is a prison emerging from a crisis. a year ago, inspectors declared it to be fundamentally unsafe and ordered urgent improvements.

but they're taking time. and one reason for that is because drugs are still being smuggled in. this harry potter book, found in a prisoner's cell, had been sprayed with a psychoactive substance similar to the synthetic cannabis spice. about 400 pages are missing. it is thought they've been cut into strips and smoked. new scanning equipment will help detect drugs — they're a major cause of instability and violence. the prison is fundamentally still unsafe, and that remains a challenge for us. every day there's an assault on my colleagues, and on other prisoners. that is regretful. but it is getting safer, but it's coming from such a low threshold that it will take time to get to a place where i and everybody can feel safe whereever we go. nottingham is one of ten prisons that are getting investment and support to cut violence. most are becoming more stable, according to the minister who's pledged to resign if the number of assaults doesn't come down by this summer.

i wouldn't have committed to going to those ten prisons and committed to reducing violence and drugs, and i wouldn't have put myjob on the line unless i was confident we can do it, but it is worth putting in context that in those ten prisons violence has been rising steadily, month on month for five years, so turning that around and bringing it down is going to be a challenge. that's certainly the case here, despite the commitment and dedication of the staff. danny shaw, bbc news, at nottingham prison. the prime minister will return to brussels next week to continue pursuing changes to the brexit withdrawal deal, despite another heavy defeat in the commons last night. a fifth of conservative mps failed to support the government's strategy, with brexiteers fearful that a no deal departure was being taken off the table. the commons leader, andrea ledsom, claims last night's defeat was "more a hiccup, than a disaster". 0ur political correspondent iain watson reports. downing street insecretary of

stating that nothing has changed. she is still trying to get a revised deal, preferably by the end of the month everyone though 60 of her mps didn't support her, ministers have been insisting she hasn't been weakened. colleagues felt it might inply they agreed with taking no—deal off the table and they weren't prepared to do that for understandable reasons. has this strengthened her hand in brussels? no. the main reason for the defeat was a communications break down with jacob rees—mogg and his european research group. he says they were signalling to the prime minister she had to keep up the pressure on brussels. i am confident we standing up brussels. i am confident we standing upfor brussels. i am confident we standing up for what people voted for, that last night's vote was a storm ma tea cup and we have brought forward constructive solutions. what he also

brought forward was a backlash against his fellow brexiteers in the european research group. one minister each went so far as to call them traitors and suggested they should go and join nigel farage in his new brexit party and there has been strong suggestions that some ministers who voted to remain in the referendum could try to push back against a brexiteers, by threatening to resign. if theresa may doesn't come back with a deal by the end of the month, some of her ministers say they could support moves to delay our departure from the european union. if they feel she is not taking steps they will have to resign. how many could go? i am hesitant to speak on behalf of collea g u es hesitant to speak on behalf of colleagues but i think we are talking of up to half a dozen. with with amber rudd who voted to remain be prepared to give up her ownjob? i plan to help the prime minister to get the withdrawal agreement agreement through and work with collea g u es agreement through and work with colleagues to do that. today the

brexit secretary was meeting ambassadors who hope to recommend a revised deal soon to avoid thousands of children across the uk are on strike from school today, joining worldwide protests against climate change. they've denounced the government for what they call an alarming lack of leadership. downing street has criticised the children's action, saying the disruption "increases teacher's workloads and wastes lesson time". jon donnison reports. from london... to brighton... cardiff... to stroud. school—children went on strike over climate change, in more than 60 towns and cities across the country. all of them young. if we don't change it who will? we are missing like our education, so that shows we are willing to give up our education to save the planet. some of them

very young. we need to save our planet because there isn't another one to go and settle on, it is just planet earth and there is only one. it all started with a swedish schoolgirl, this 16—year—old often single—handed protests each friday have spread into a global movement. this was in australia, in november. where an estimated 15,000 children took to the streets. and this was berlin. just last month. greta is now addressing un climate conference, and has a message for the grown ups. you are not mature enough to tell it like it is. even that burden you leave to us children. and on the bbc this morning, one young protestor here was putting the government on the spot. what action will you be taking to reassure our generation about climate change? george, it is great

to see you, if i was 40 years younger i would be out with you today, even though i don't want to create any extra workload for teachersing for we want people who are passionate to be learning the skills we need to solve this problem. you will probably learn them best in the classroom and the prime minister's spokesperson said the disruption was wasting lesson time, and increasing teacher's workload. but in a tweet, the labour leaderjeremy corbyn called the strike inspiring. and the leader of the green party caroline lucas said young people were offering more leadership than most politicians. but what about teachers? they are going to in many ways feel a sense of sympathy, proud of the their passion but what we are responsible for is the welfare of young people. but for the young people on the streets today, it is the welfare of the planet that matters, and organisers of the strikes want them to become a weekly event.

our top story this lunchtime. donald trump invokes emergency powers to pay for his border wall with mexico. and coming up — cleaning up space. the new tools being used by british engineers to tackle orbitaljunk. coming up on bbc news, caster semenya receives the support of south africa's government, in her fight against a rule to limit testosterone in female athletes. the runner takes the case again to court next week. black holes and neutron stars — they're some of the great mysteries of space. now the british and us governments are spending more than £20 million upgrading the machine that first made history by detecting gravitational waves three years ago. those waves are ripples in space caused by objects moving at very high speed. well, the new plans have been announced in washington, from where our science correspondent pallab ghosh has sent this report. it is one of biggest discoveries in

the history of science. the detection of the gravitational waves, caused by two black holes colliding in a distant galaxy. we have detected gravitational waves. we did it. that was three years ago. now, the pairof4 that was three years ago. now, the pair of 4 kilometre long instruments that made the discoveries are to be given an upgrade. they are already the most sensitive instruments in the most sensitive instruments in the world. inside, are lasers and mirrors that measure the tiny shifts caused by these mysterious waves from outer space. gravitational waves a re from outer space. gravitational waves are ripples that are sent across the universe, when the gravity at a certain point in space suddenly changes. triggered by huge

events like distant stars exploding. 0ver events like distant stars exploding. over the past three years the instruments have detected the collision of 10 black holes, scientists will be able to detect many more, maybe three each day. harder to detect are the collision of giant suns that have collapsed. called neutron star, just one spotted so far. the new machine will be able to detect 13 each month. and astronomers should be able to see much deeper into the universe, further back in time. even to when it all began, with the big bang. the upgrade will be carried out here, at the institute for gravitational research at glasgow university, they from the the expertise to build a high precision instrument needed to measure the tiny distortions the waves create. ultra thin glass fibres are being drawn. these will be used to suspend

these mirror, they have to be kept absolutely motionless and be the stillest objects on the planet. we measure the motion of these mirror, it is almost none a all but the tiny motion, we measure that and we have to extra ct motion, we measure that and we have to extract that information without losing anything, and that means improving the efficiency of the optic, avoiding any light, going where we don't want it to go and a fairly complicated set of little improvements that all together again will roughly double the performance of the detector. the new up grades will come online in five years' time. a development that scientists say will enable them to answer some of the universe india's prime minister has warned that militants responsible for killing at least 40 security personnel in kashmir will not go unpunished. narendra modi was speaking after an emergency meeting of his security cabinet in delhi. yesterday, a suicide bomber drove a truck packed with explosives into a convoy transporting members

of the central reserve police force. the attack is the deadliest in the region for three decades. the royal bank of scotland, which is partly owned by the government, has announced its profits have more than doubled in the past year to £1.62 billion. but the chief executive has warned that the high level of uncertainty over brexit could have a bigger impact on the uk economy than the bank of england predicted and says the bank has taken steps to protect its customers. it has been an expensive exercise, very distracting but we are ready for customer, we have put out a growth fund for those businesses that are concerned an they may have to prebuy a number of raw materials for their production, we have put aside 3 billion for a growth fund to

help them with their retail sales increased by 1% last month compared to december. the office for national statistics says clothing discounts appear to have encouraged shoppers to make purchases. the bounce back from the decline in retail sales seen at the end of last year was stronger than most analysts expected. engineers say they've successfully found a new way to try and tackle the build—up of space debris. a team from the university of surrey has used a harpoon—capture system on board a satellite to collect orbitaljunk. 0ur science correspondent rebecca morelle reports. this is the moment a harpoon was fired in space. striking a target almost dead centre, it was filmed 250 miles above the earth. it's the latest experiment from the remove debris spacecraft. led by surrey university, it's a mission that is testing out the technologies that could clean up space junk. it was absolutely a success and the goal of the experiment

was to hit the target and that's what we did. it's important because there's so much debris up in space, from spacecraft that are no longer operational to bits of rocket body, and we need to start clearing some of this debris out of the way to make way for new spacecraft. space is becoming increasingly cluttered. it is estimated there are now nearly 8,000 tonnes of debris, with 800,000 pieces the size of a marble or bigger, and each piece has the potential to do some serious damage. in 2016, this crack in the window of the international space station was thought to have been caused when a tiny fleck of paint hit it. bigger objects could do even more harmful. scientists are particularly worried about a european satellite the size of a double decker bus that stopped working in 2012. it's now threatening other satellites in its path and needs to be remove from its orbit. last year, the remove debris spacecraft also tested a net, proving it could catch a passing satellite. it's the first mission to try and address this problem.

and it's also used its onboard cameras to track a tumbling target. essential for hunting down any rogue space litter. its final test will be in the coming weeks. it's set to burn up as it returns to earth, preventing it from becoming a piece of space junk itself. the hope is now that future missions can be scaled up so the celestial deep clean can begin. the author andrea levy — whose work includes the award—winning novel small island — has died of cancer at the age of 62. her writing chronicled the lives of the windrush generation and encapsulated for many what it meant to be black and british after the second world war. 0ur arts correspondent david sillito looks back at her life. newsreel: arrivals of children. the empire windrush brings to britain 500 jamaicans, many are ex—serivcemen who know

england. in 1948, andrea levy's father arrived on the empire windrush. it was the inspiration for her novel that charted with wit and compassion the hopes and struggles of a generation. small island. you think your white skin make you better than me, don't you. we both finish fighting a warfor a better world. we was on the same side. when it first came out, you know, i sort of said to the publicist, look, you know, give me a basket, i'll take them door—to—door. you know, i mean, i really thought nobody was going to be interested. in 2005 it won whitbread book of the year. small island. andrea levy grew up in london and in her 30s began to write. much of her work driven by her own curiosity about where she had come from. a story that eventually took her back to britain's role in the caribbean slave trade. for every one slave that went to america,

12 went to the caribbean. it was massive. i have seen books on british history that don't mention slavery, you know. and you just sort of — it beggars belief. me here. the characters she create was a house slave, who bears a child to an estate master. and then, later, she found that that was the story of her own great—great—grandmother. andrea levy's life and work was rooted in the story of two small intertwined islands. britain and jamaica. let them say what they like. because i am the bustard child of empire. and i will have my day. the author andrea levy who's died aged 62.

now could this be the fastest child in the world? this is seven—year—old rudolf ingram from florida — he's known as ‘blaze' and ran 100 metres in a time of 13.48 seconds. he hopes one day to beat usain bolt‘s world record 9.58 seconds. his father has been telling bbc radio 5—live how his son got into running. he was like three years old and we were watching the olympics and the next morning he woke up, sprinted out of the room. from that day on it was like a guy who's interested in track.