British Prime Minister Theresa May is set to be confronted by a group of her Conservative Party's leading Brexit supporters at a crisis meeting.
The Sunday afternoon session at Chequers, the prime minister's country residence, is expected to include prominent Brexit advocates including former foreign secretary Boris Johnson and Conservative MP Jacob Rees-Mogg.
May is struggling to keep her Brexit withdrawal plan alive and to keep her grip on power as opposition to her leadership mounts.
The Sunday Times reported that a Cabinet coup is under way with a growing number of Cabinet members seeking to oust May or force her to set a date for her departure.
Her authority has been weakened by her inability to build a consensus in parliament behind her Brexit withdrawal plan, which has been defeated twice.
The Sunday Times cited 11 unidentified senior ministers and said they had agreed that the prime minister should stand down, warning that she has become a toxic and erratic figure.
"The end is nigh. She will be gone in 10 days," the newspaper quoted an unidentified minister as saying.
"Her judgment has started to go haywire. You can't be a member of the cabinet who just puts your head in the sand," the newspaper cited a second unidentified minister as saying.
The Sunday Times reported that May's de-facto deputy, David Lidington, is one contender to be interim prime minister but others are pushing for Environment Secretary Michael Gove or Foreign Secretary Jeremy Hunt.
The newspaper said cabinet ministers would confront May on Monday. If she refuses to go, ministers would threaten to resign.
However Gove said on Sunday that May "absolutely" had his support, adding that it was a time for "cool heads" to focus on getting her twice-rejected Brexit agreement approved by MPs.
"I think it is not the time to change the captain of the ship, I think what we need to do is to chart the right course, and the prime minister has charted that right course by making sure that we have a deal that honours the referendum mandate," he said.
May's office declined to comment on the reports.
Earlier a Downing Street source, speaking on condition of anonymity, told Reuters that a Saturday Times report that there were discussions in May's office about her departure was incorrect.
Betting odds indicate there is now a 20 per cent chance that May will be out of her job by the end of this month, Ladbrokes said on Saturday.
Brexit had been due to happen on March 29 before May secured a delay in talks with the EU on Thursday.
Now a May 22 departure date will apply if parliament rallies behind the British prime minister next week and she is able to pass her deal.
If she fails to do so, Britain will have until April 12 to offer a new plan or decide to leave the EU without a treaty.
