donald trump defies his critics, taking the drastic step of calling a national emergency to build a border wall with mexico. trying to make good on a campaign promise he says the us faces an "invasion" of migrants, drugs and human traffickers. in areas where we don't have a barrier, then...very hard to make america great again. but democrats say the president's claims are bogus and they'll fight him in the courts. also on the programme: inside the camp where a british jihadi bride is living. she wants to come back to the uk, but the head of mi6 warns of the threat posed by returning islamic state extremists. show me what democracy looks like. this is what democracy looks like. schoolchildren make their voices heard, leaving classrooms across the country to protest climate change. a record number of children are now in care in england, but often the reasons for deciding to put a child in care aren't always clear. you see, auntie carol explained

to me as i sat on my case, jamaica used to be part of the british empire. and a celebrated chronicler of the black british experience, the author andrea levy has died. she was 62. and coming up on bbc news, newport manager mike flynn tells us he's hoping to pull off the biggest fa cup shock of all time when they take on manchester city in the fifth round tomorrow. good evening and welcome to the bbc news at six. donald trump has defied his critics, many in his own party, by declaring a national emergency to bypass congress to get the billions of dollars he says he needs to build a border wall with mexico. at a news conference at the white house, he said a barrier was needed to stop an "invasion" of drugs,

gangs, human traffickers, and undocumented migrants. however, democrats say the move is unconstitutional, because the president has exaggerated problems on the border to try to fulfill a rash campaign promise and they'll fight him all the way to the supreme court. but what is the truth on the ground? well, our correspondent danjohnson is in san diego on the us—mexico border. donald trump's basic plan is that by building a wall, securing the border, you can focus the drugs, the goods, the people who are crossing, whether they are criminals or asylum seekers, two points like this, the official border crossing, and you can free up border agents to focus their energy here too. but there will be disappointment from people on donald trump us inside that he has failed to get the $5 billion that he wanted, and his democratic opponents are already saying that

this is a manufactured crisis and an illegal declaration. i should warn you there are flashing images coming up. this dividing line has become the defining issue of donald trump's presidency. it's split american opinion and gridlocked government like never before. the president of the united states... now there's a funding deal, but it falls $4 billion short of donald trump's target, so today he raised the stakes. we're going to confront the national security crisis on our southern border, and we're going to do it one way or the other. we have to do it. they say walls don't work. walls work 100%. i'm going to be signing a national emergency. we are talking about an invasion of our country... with drugs and human traffickers... with all types of criminals and gangs. these are the final footsteps of that human—trafficking trail. whoa, whoa! after a 2500—mile journey 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 a thousand more who cross illegally every day. there's already a fence of one kind or another along a third of the 2000—mile border. 18—foot steel slatted, concrete filled barrier with anti—climb plates on top... here, it's already being upgraded, and it's making a difference. this barrier takes a 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. so the chief here shares the president's ambition to extend this fence across these hills.

we have to have a barrier, or we'll 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. but the numbers are way down, aren't they? i would say it's nothing like it was, i would say it's changed. after spending time here, it would be easy to question the president's rhetoric — his talk of a crisis, of 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, and border patrol agents say it is unsustainable. manpower, horsepower — all of it is stretched. donald trump has staked so much on this border and seeing this fence go further. now it looks like this fight will go to court. danjohnson, bbc news, san diego. our north america editor, jon sopel, joins us now. what has been the reaction to the

president's decision? well, i don't think there's been surprise, clive, because donald trump faced a choice that was pretty unpalatable, he was either going to admit defeat, that there wouldn't be the funds for his border wall, and the democrats would have won, or we could have chosen the nuclear option and declare a national emergency. we have already had some reaction from democrats, nancy pelosi, the speaker of the house, the minority leader in the senate, saying this unlawful declaration of a crisis that does not exist does for greater violence to our constitution and makes america less safe. i think what they are doing is setting the stage for some kind of legal challenge. that will delay any building work. it could go all the way to the supreme court, and that would be a fascinating deliberation that they have to make, because on the one hand it is absolutely true, thousands of people, as we saw in danjohnson‘s

thousands of people, as we saw in dan johnson's report, are thousands of people, as we saw in danjohnson‘s report, are trying to get across the border illegally, but if you look at the situation statistically, the number of people trying to get across is actually been falling, and most of the drugs that are coming into the country are coming across the established border crossings. so what i think the supreme court, if it gets that far, will have to weigh is the simple question — is this a genuine national emergency, or is this a political emergency for donald trump? 0k, jon, thank you for that, john trump? 0k, jon, thank you for that, john zobel live at the white house. the head of mi6 has warned that so—called islamic state still poses a significant threat and is regrouping for more attacks, despite losing much of its territory in the middle east. in a rare public briefing, alex younger says he's deeply concerned about jihadists returning to europe, who've acquired "skills and connections" making them potentially very dangerous. he was speaking after the east london teenager shamima begum said she wanted to return to the uk after running away to become a jihadi bride four years ago. our home affairs correspondent daniel sandford has the story. inside his camp in northern syria,

and the women and children who fled from the fighting in one of the last strongholds of the islamic state group. filmed earlier this month, this is where the former bethnal green schoolgirl shamima begum was ten, along with other british women who've been with is for four years oi’ who've been with is for four years or more. today alex younger, the head of the secret intelligence service, mi6, said, experience tells us service, mi6, said, experience tells us that once someone has put themselves in that sort of position, they are likely to have acquired the skills or connections that make them potentially very dangerous. some 850 people left the uk to join is, potentially very dangerous. some 850 people left the uk tojoin is, and around half have already returned. at this morning the home secretary, sajid javid, said, if you have supported terrorist organisations abroad, i will not hesitate to prevent your return. if you do

manage to return, you should be ready to be questioned, investigated and potentially prosecuted. we have to be clear that people who leave this country to support that regime are people who, if they do return, have to answer for their actions. what does that mean for shamima begum, who left the uk aged 15, has lost two children and is pregnant with a third? could she have her citizenship taken away? if she doesn't have another nationality, as i believe to be the case, it is morally unacceptable to refuse her entry, as well as legally unacceptable, because otherwise she would be stateless, and no person in the world can be stateless under the law. so if she can make it to the uk, she might get in, but she still seems hardened and radicalised. did you ever see executions? no, but i saw beheaded heads. these are the heads of captives? but an expert in

de—radicalisation says is supporters can be turned round. we know, in the uk, we have worked over the past ten yea rs uk, we have worked over the past ten years with fairly hard—line extremists who have announced their ideology, have remorse for their actions, and have taken part, actually, in helping others move away from extremist tendencies and violent ideologies. the kurdish red crescent says there were over a thousand new arrivals at the camp just this morning. decisions will have to be made soon about what to do with the british is supporters among them. daniel sandford, bbc news. here, schoolchildren across the uk have been taking part in a day of protests, calling for action on climate change. organisers say pupils walked out of schools in more than 60 towns and cities to highlight what they see as a lack of action by the government. manchester is one of the places where children took to the streets, from where frankie mccamley reports. we are angry that the government's not doing anything, but we also see

it as important to fight for our futures. to all the politicians, listen to what we have to say. you failed at saving your own future, so now can you try and save ours? there's no time to rest. we have to do something to save the planet. chanting: this is what democracy looks like! different voices, one clear message. today was a day led by the children, for the children and their future. thousands campaigned in dozens of protests across the country. they say you don't have a voice! a call for action in sheffield... what do we want? climate action! chanting in ullapool. .. marching in brighton... a real sense of urgency in cardiff and, in manchester, there was music. # born to love in everyone... before nine—year—old lilia had her say. i'm worried about climate change because of the animals. would you like it if your home was disappearing in front of your eyes?

this is clearly the first time many of these pupils have ever walked out of school and, just by looking at the age of some of these, the first time they've ever been on a protest, but their message is clear. they want to protect the future of the planet and safeguard their future. the action is part of a much wider global movement, inspired by 16—year—old greta thunberg from sweden. she's been striking from school every friday, calling on her government to lower its carbon footprint. you are not mature enough to tell it like it is. even that burden you leave to us children. her persistence later sparked protests across the world, from australia to belgium and ireland earlier this week. the government has said today's protests are a waste of lesson time and increasing teachers‘ workload, but the threat of school disciplinary action pales in significance to the danger these youngsters think the planet is under from climate change. frankie mccamley,

bbc news, manchester. police in northern bulgaria have launched an inquiry into the trade in illegal fighting dogs following a bbc investigation. they're looking for ivaylo nikolov, who offered to sell bbc investigators a "proven" dog ready to take part in organised fights. mr nikolov denied he was involved when confronted by the bbc. a new study suggests the majority of knee and hip replacements last much longer than previously thought. researchers at the university of bristol say replacement joints can remain effective for up to 25 years. it's hoped the findings will help doctors and patients decide when to carry out surgery. 0ur health correspondent jenny walrond has more. 80—year—old wendy, 17 years on from a hip replacement, cycles more often than she drives. i was in intense pain, so it restricted everything i wanted to do, even cycling

was getting quite difficult. and then i had the operation, and i woke up, and it was like a new person, it's magic. hip and knee replacements are two of the most common types of surgery. until now, doctors haven't been able to give patients accurate information about how long they will continue to work. but a study published in the lancetjournal shows that manyjoint replacements last for 25 years. for knees, it's over 80%, and almost 60% of hip replacements. much longer than previously thought. having surgery a second time on a replacement is more expensive and less likely to be successful, so knowing the joints will last longer could help both patients and surgeons to make more informed decisions. the main implication is that patients can go into the surgery, or when deciding whether to have surgery, with their eyes open.

they understand exactly what the risks are and exactly how long this hip replacement or knee replacement is likely to last. the nhs in england and wales carries out almost 200,000 hip and knee replacements each year. knowing how long they last allows the health service to plan its resources at a time when our ageing population means more people will need them. today's research can reassure patients like wendy that they too can stay active for longer. she's hoping her hip will last at least another ten years. one of my grandsons wants me to take him to barbados when i'm 90, so i've got to live till i'm 90 and take him to barbados, like he wants me to do. so hopefully it'll be good. jenny walrond, bbc news, bristol. our top story this evening... president trump defies his critics, taking the drastic step of calling a national emergency to get money

to build a border wall with mexico. and a celebrated chronicler of the black british experience, the author andrea levy has died. coming up on sportsday on bbc news, the fa cup fifth round gets under way tonight, with qpr hosting watford in the first of eight matches across the weekend. next week, mps looking into disinformation and fake news are expected to publish their final report into the way our personal data has been manipulated for political influence, particularly at times of intense political controversy and as those at the highest levels of power increasingly choose to level the charge of fake news atjournalists across the globe. here's our media editor, amol rajan. when you report fake news, which cnn does a lot, you are the enemy of the people. in just a few years, the phrase "fake news" has entered mainstream culture.

then they've got the nerve to say we're fake news. you and your colleagues have fallen into this trap of fake news. it's a calculated and corrosive term, often deployed by those trying to discreditjournalism, but the term fake news captures an urgent issue confronting modern democracies — disinformation in the digital age. in america, authorities are investigating social media's role in russian interference in the presidential election of 2016. the nearest thing in britain is the house of commons select committee enquiry into disinformation and fake news. over the past year, it has taken evidence from regulators and tech companies and those at the centre of allegations around the targeting of voters during the brexit referendum. the enquiry is looking at four areas in particular — first, whether social media firms are neither platforms nor publishers but a new kind of company which has legal liability for harmful or illegal content. then there's the issue of electoral law. the committee wants new rules

for digital campaigns, not least around the issue of shell corporations being used to hide identities. next, what was the precise role of cambridge analytica? the committee has looked at the impact of the british data firm and has said its ceo misled them. finally, there's the kremlin question — to what extent, if any, did russia weaponise information during the brexit referendum, and why is there such a gulf between the government's warnings about security and the response of tech companies? facebook is taking disinformation more seriously and has appointed the charity full fact as its first independent fact—checkers in britain. one thing i'm aware of is it might not be facebook in ten years' time, or it might notjust be facebook. we're going to need to write rules through open, democratic, transparent processes that apply to all these companies. last year, facebook was fined the maximum half a million pounds by the information commissioner for serious breaches in data protection law. have you seen satisfactory evidence that they've learned and changed? i am hopeful that we'll see

more of that change. that suggests we haven't so far. i haven't so far. i think it's yet to be seen. what do they need to do to comply with this regulatory regime which they are currently not doing? it's not good enough to say, here's what we're doing. we need a proof point and we need... facebook can't mark their own homework. social media platforms like to think they're a benefit to democracy. across the west, that's in dispute. amol rajan, bbc news. a company which monitors thousands of offenders — under the government's partial privatisation of the probation service — has gone into administration. the firm, working links, was criticised by inspectors who said it was "buckling" under the strain of commercial pressures. here's our home affairs correspondent, danny shaw. what are the implications for this company going bust?

i think it's a serious blow to the probation system for a start, the system in england and wales. it creates huw system in england and wales. it creates hquones system in england and wales. it creates huw jones entity system in england and wales. it creates hquones entity for all those involved in probation services. —— huge uncertainty. working links was one of eight companies awarded contracts in 2016, when chris grayling asjustice secretary partially privatised probation services in england and wales, but working links has struggled to deliver services. it had contracts in wales in south—west england and an inspection report into devon, cornwall and dorset found really that company wasn't delivering properly that people were being put at risk because of the huge workload staff were faced by, they were facing huge commercial pressures not get fines for their company, and because of that the justice secretary, david gauke, has intervened. he has transferred the services from working links to another provider called ctech, but

working links will go into administration. it raises huge questions over the future of probation services, and all of the contracts across england and wales are being terminated next year, two yea rs are being terminated next year, two years earlier, and in wales, probation will be renationalised. latest figures suggest a record number of children are living in care in england, more than 75,000. but the reasons for deciding to put a child in care aren't always clear, with family courtjudgments usually shrouded in secrecy. but, thanks to a court of appeal decision today, we can now report one disturbing story. 0ur correspondent sanchia berg has been talking to one mother about her struggle with the courts. taking a child away from their home and family into care is the most drastic step any court can take. it changes lives forever. 0ne mother almost lost her two—year—old daughter. the case was based on what the court of appeal called the slimmest of evidence.

we've had to protect her identity. i was shocked. i just didn't understand. it made me question the family law system, because what had happened, didn't justify putting her up for adoption. the little girl suffered from allergies and was prescribed an epipen. on two occasions, when she seemed to be suffering an attack, her mother injected and took her to hospital. however, doctors thought she might be deliberately harming her daughter. the mother was arrested, her daughter taken into foster care. no charges were brought, but the family court said she should be adopted, after two care plans failed. i was told my chances of winning were nil. but i thought i've got to try to do my best for my daughter. the mother appealed, and won. after fighting for years, she now has her daughter home. she's scathing about the family court. i don't feel like it protects families. it protects bad practice, because basically, they are a law

unto themselves and nobody is able to challenge them, because it's all done in secrecy. the case was heard here in portsmouth, but only came to light because it went to the court of appeal. for many years now there's been talk of opening up the family courts but in some places that simply hasn't happened. so we have very little detailed information about care cases in some parts of the country. we asked southampton city council if they had any comment on this specific case, and they didn't respond to that issue. this case cost the mother £60,000, money she struggled to raise. at a time when there are more care cases and less money, many say there must be more scrutiny of the powerful family courts. the award—winning british author andrea levy has died. she was 62 and had been receiving treatment for breast cancer.

the daughter of windrush generation parents who came to britain from jamaica in the late 1940s, her books chronicled the highs and lows of the black british experience, most notably in her celebrated work small island. lizo mzimba looks back at her life. the empire windrush brings to britain 500 jamaicans... the empire windrush brings to britain 500 jamaicans. .. in 1948, andrea levy's farber arrived on the windrush, the inspiration for her novel charting the hopes and struggles of a generation, small island, which won multiple awards and was adapted for tv and stage. when it came out, i said, just give mea when it came out, i said, just give me a basket, i'll take them door—to—door. i really thought nobody would be interested. you think your white skin makes you better than me, don't you? we both finished fighting a war for a better

world. we we re finished fighting a war for a better world. we were on the same side. finished fighting a war for a better world. we were on the same sidem anybody wants to have a look at how the windrush generation arrived here, and how we, the sons and daughters of that generation, survived and are surviving, they have to refer to andrea's work. that's why, for my generation of black people in this country, there is always a andrea levy book on book shelves. andrea levy's work was driven by her own curiosity about where she'd come from. it was a story which eventually took her back to britain's role in the caribbean slave trade. for everyone slave who 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. the character she created was a slave who bore a child to an estate master, and later she discovered that was the story of her own great, great grandmother. andrea levy, an author whose life and work was rooted in the story across generations of two small islands, britain and jamaica. andrea levy, who has died at age 62. time for a look at the weather. here's tomasz schafernaker. what a day—to—day! absolutely stunning, almost picnic weather, and in wales temperatures got up to 17.5 degrees in rhyl, warmer than yesterday, and for many of us it was around the teens. maybe in the morning, but once the sun came out it felt like march or april. tonight, it will be mild for a time

but, where the sky is clear, temperatures take a tumble and we get a big range between the mornings and afternoons. clear skies across many parts of england and wales, and we'll talk about this cloud in a second, but much of europe is being dominated by that ridge of high pressure, extending all the way into eastern europe and the balkans. many countries in europe are experiencing unusually high temperatures. as we go through tonight, there are weather fronts skirting the north—west of the uk, so we have some cloud here now, which will continue through the night. generally, there will be more cloud drifting in our direction through tonight and into tomorrow, because we are on the edge of the high pressure. there is also a low in the atla ntic pressure. there is also a low in the atlantic drawing up a mild airfrom the south and the azores but, with that, weather fronts close by, the south and the azores but, with that, weatherfronts close by, which is quite moist air. through the night and into the morning, a lot of low cloud in the west, and some of

it will move inland as we go through saturday. but temperatures will get up saturday. but temperatures will get up to around 13 or 14, so a shade lower, and the best sunshine in eastern parts on saturday. through the weekend, saturday into sunday, sunday will broaden up a bit, and i suspect more eastern and southern areas will get the best sunshine, with temperatures up to 15 or so. the indication is that the week ahead, next week, is still looking very mild. spring is hair! that's it, so goodbye from me. now on bbc one, let'sjoin our news teams where you are. good evening. this is bbc world news, the headlines: the us president donald trump has declared a national emergency in an attempt to bypass congress and secure funding for his mexican border wall. we are going to be signing today, a

national emergency and it is a great thing today. he ran away from her home in london, aged 15, to be with militants, said she wanted to come home to have her baby. thousands of pupils skip school and ta ke to thousands of pupils skip school and take to the streets in protest against time to change. award—winning author andrea levy, his work chronicled the windrush generation, has died aged 62.