One of the terrorists who carried out the London Bridge attack worked last year for London Underground at Southwark Tube Station, Mayor of London Sadiq Khan confirmed on Thursday.
The Mayor was answering a question from Labour London Assembly member Len Duvall who noted that Khuram Butt worked at stations on the Jubilee line whilst on an MI5 watchlist and after featuring in a Channel 4 documentary The Jihadis Next Door.
"Khuram Butt worked for Transport for London for under six months in 2016 as a trainee customer service assistant at Canada Water, Southwark and Westminster stations," said the Mayor.
"He was employed in May 2016 and ceased to be a TfL employee in October last year.
"I am informed that he failed his probation because of extremely poor attendance."
The Mayor told the assembly that since the London Bridge attack transport commissioner Mike Brown has met Metropolitan Police commissioner Cressida Dick to discuss enhanced vetting of TfL staff.
Butt was one of the three men shot dead by police in Borough Market after killing eight people on London Bridge and in the market area on Saturday 3 June.