London (CNN)One of Theresa May's most senior Cabinet ministers has raised the prospect of a second referendum to break the Brexit deadlock, as speculation over the future of the beleaguered UK prime minister and her twice-defeated divorce bill reaches fever pitch.
A day after hundreds of thousands marched in central London to demand another public vote, Chancellor Philip Hammond said a second referendum - likely to be one of the options put to lawmakers in the coming days - was a "coherent proposition" that deserves consideration.
MPs could vote as soon as Monday on that and a series of other Brexit alternatives, in an attempt to find a route out of the country's chaotic political standstill before the new April 12
deadline imposed by the European Council on Thursday.
But its anticipated defeat would set Britain on another collision course with the EU, with any alternative other than a no-deal break likely requiring the government to seek a further extension and possibly forcing the UK to take part in European elections in May.
May 'facing coup; from her cabinet
The chances of May being in office to see any Brexit strategy through are increasingly being thrown into question, with several senior Cabinet ministers reportedly preparing to force a coup when they meet the Prime Minister on Monday.
The Sunday Times newspaper reported that 11 Cabinet ministers -- almost half of her senior government ministers -- are to confront May with an ultimatum, urging her to quit in return for support for her Withdrawal Agreement.
The paper reports that her de facto deputy and close ally David Lidington is being lined up to take over, while The Mail on Sunday says Environment Secretary Michael Gove is the "consensus choice" for the job. Both have since stressed their loyalty to the PM.
Speculation was heightened further when George Freeman, a Conservative MP and former policy adviser to May, said on Saturday evening that it was "all over" for May.
"I'm afraid it's all over for the PM. She's done her best. But across the country you can see the anger. Everyone feels betrayed," Freeman tweeted.
I'm afraid it's all over for the PM. She's done her best. But across the country you can see the anger. Everyone feels betrayed. Government's gridlocked. Trust in democracy collapsing. This cant go on. We need a new PM who can reach out & build some sort of coalition for a PlanB.
Downing Street told CNN that it would not comment on speculation from newspapers, and that the rumors have not affected the schedule for the upcoming week.
Those heightened calls for a so-called "People's Vote" could also provide May's Brexit deal an unlikely lifeline, with some senior opposition figures suggesting they would vote in favor of the plan if it were then put to the people in a confirmatory referendum.