DAVID Cameron could be toppled as Prime Minister by the end of the summer, Tory MPs have said.

Witney MP Mr Cameron is said to be facing a leadership challenge over his stance on the the EU referendum on June 23.

Fellow Conservative MP Nadine Dorries said he had to go as he had "lied profoundly" over warnings about what would happen if Britain votes to leave the EU.

To trigger a contest 50 Tory MPs would have to write to the party’s 1922 Committee of back benchers.

Justice Secretary Michael Gove, Home Secretary Theresa May and former Mayor of London Boris Johnson have been touted as possible successors.