Theresa May is facing the threat of a revolt by Remain-supporting ministers ahead of a crucial cabinet meeting on her Brexit negotiations.
Three say they will resign unless the PM agrees to take no-deal off the table, and there are suggestions that more are prepared to follow suit.
The BBC’s Nick Watt says the feeling is Mrs May will “lean into” their demands and Brexiteers have been told to expect a “very difficult message”.
No 10 would not comment on the reports.
The government position is set to be thrashed out at a cabinet meeting on Tuesday morning, where Brexit is the only item on the agenda.
Read: Theresa May under pressure to consider Brexit delay
After that, the prime minister will make a statement to the Commons, updating the whole House on her negotiations.
She has just returned from a summit in Egypt where she held a number of meetings with EU leaders and continued to press for more concessions to placate critics of her deal, in particular on the Irish border backstop.
News of the growing unrest within the cabinet came after Labour announced a significant shift in its policy – a decision to back another referendum if its own alternative Brexit plan is rejected.
What are the ministers demanding?
Mrs May’s Brexit deal was comprehensively rejected by MPs on 15 January and she has said they’ll get a second chance to vote on it – possibly with some changes – by 12 March.
But writing in the Daily Mail, ministers Richard Harrington, Claire Perry and Margot James said Mrs May must promise now that she will rule out the possibility of the UK leaving the EU without a deal if her agreement is rejected again, and instead seek a way to delay.
If she does give such a commitment, they write, it “would be greeted with relief by the vast majority of MPs, businesses and their employees”, adding that the UK risked being “swept over the precipice” in the event of no-deal.
If she does not give in, they said, it would be in the “national interest” for them to resign and instead back a move to force a delay upon her.
That move comes in the form of an amendment – a legislative tool – being put before the Commons by Labour’s Yvette Cooper and Conservative Oliver Letwin on Wednesday.
If passed, it would give MPs the power to demand a delay to Brexit if a deal cannot be agreed by 13 March.
Three other senior cabinet ministers, Greg Clark, Amber Rudd and David Gauke, have already signalled they could also be prepared to vote for the Cooper-Letwin option if there is no breakthrough in the next few days.
Mrs May has long resisted any suggestion that the UK’s departure from the EU could be postponed beyond 29 March.
Read: Brexit must not be frustrated, Theresa May vows
But one of the ministers who is threatening to resign told BBC Newsnight they were now hearing “good mood music from Downing Street” about the possibility of a shift in the prime minister’s position.
How has Labour’s position changed?
Labour has said it will support the Cooper-Letwin amendment, making its chances of success far higher.
But leader Jeremy Corbyn also wants to use Wednesday to put his own plan for Brexit – which includes a “comprehensive customs union” with the EU and “close alignment” with the single market – before the Commons.
He told his MPs on Monday night that if – as expected – that plan is rejected, the party will formally throw its weight behind another public vote.
Exactly what form of fresh referendum Labour would back – or when it would like one to happen – is not clear though.
Shadow Brexit Secretary Sir Keir Starmer told the BBC that the precise question would be decided by Parliament, but he said: “It should be between a credible leave option or remain. If the prime minister gets a deal through, it should be subject to the lock of a public vote.”
Source: BBC