Transport for London's commissioner has refused to quit over delays to the Crossrail project after a report suggested he should consider doing so.
Mike Brown told the London Assembly transport committee he was "fit" to do his role and the "buck stops" with previous Crossrail management.
The new railway across London was due to open in December 2018, but may not open until 2021.
The committee's report said Mr Brown "watered down" risks to the project.
But at a meeting on Thursday at City Hall, Mr Brown said: "I'm not reflecting on whether I'm fit to be in position. I believe I am, I've got [the] full support of the mayor, and that's the end of the issue for me."
The committee said emails between Crossrail and Transport for London (TfL) showed risks to the timetable, which were flagged to London Mayor Sadiq Khan, were "watered down" by Mr Brown.
But Mr Brown told the meeting that reports showing "emerging risks" to Crossrail's schedule were "very explicitly highlighted" consistently at meetings with Mr Khan throughout 2018.
"Although there were risks - some of them red, some of them amber- fundamentally in all of those reports, right up until the end of August last year, the date of 9 December was being held," he said.
But committee chairman Caroline Pidgeon said: "It's very clear the messaging that was going to the mayor was not as clear as it should have been."
Mr Brown also disputed claims by committee members that Crossrail's ex-chairman, Sir Terry Morgan, said Mr Brown had been made aware of the delay to the 9 December opening date before it was announced at the end of August.
Three emergency cash injections have seen the cost of Crossrail, or the Elizabeth Line, rise from £14.8bn to £17.6bn.