Conservative MP and Leave campaigner Nadine Dorries has said Prime Minister David Cameron will be "toast within days", depending on the result of the European referendum.
Speaking to Robert Peston on ITV's Peston on Sunday, she said her "letter is already in", along with 50 other MPs, asking for the Prime Minster to stand aside.
She said "David Cameron might just survive if there's a 60/40 majority to Remain" but warns anything less should see the end of his leadership.
"He has lied, profoundly. There are many issues at which David Cameron has told outright lies and the trust, because of that, has gone from both him and George Osborne", Dorries said.
She added: "I always have backed the only politician in Westminster who has a proven track record of achievement, and that's Boris Johnson".