if they are ulez compliant, they do not have to pay the fee for the ulez, if it is expanded for greater the report prepared by the independent experts. we will look at all of the four options, tfl will go away, look at all four options, engage, consult, have an impact assessment, work out which scheme works best for londoners, in relation to discounts and exemptions but i'll make a decision baed on the advice from tfl. mayor khan, thank you very much. as you heard there, feasibly this clean air charge could be introduced within the next two years or so but it's still very early days. a campaign's been launched to protect a cave which has been unearthed during work on a devon housing development. historical artefacts have been found on the site at the sherford development near plymouth. campaigners are now trying to protect the cave from being closed over or filled in. john ayres has the story. yes, there is also excitement about what has been found at the cave in sherford, and experts are analysing it now. i want to be clear, this is not sherford, this is kent's cavern which is one of t