British Prime Minister Theresa May said on Sunday toppling her would risk delaying Brexit and she would not let talk of a leadership challenge distract her from a critical week of negotiations with Brussels.
Since unveiling a draft divorce deal with the European Union on Wednesday, May's premiership has been thrust into crisis by the resignation of several ministers, including her Brexit minister, and some of her own members of parliament are seeking to oust her.
More than two years after the United Kingdom voted to leave the EU, it is still unclear how, on what terms or even if it will leave as planned on March 29, 2019.
May has vowed to fight on, but with both pro-EU and pro-Brexit lawmakers unhappy with the draft agreement, it is not clear she will be able to win the backing of parliament for it, raising the risk Britain leaves the EU without a deal.
"These next seven days are going to be critical, they are about the future of this country," May told Sky News. "I am not going to be distracted from the important job.
"A change of leadership at this point isn't going to make the negotiations any easier ... what it will do is mean that there is a risk that actually we delay the negotiations and that is a risk that Brexit gets delayed or frustrated."
To trigger a confidence vote, 48 of her Conservative lawmakers must submit a letter to the chairman of the party's so-called 1922 committee, Graham Brady.
More than 20 lawmakers have said publicly that they have submitted a letter, but others are thought to have done so confidentially. Brady told BBC Radio on Sunday the 48 threshold had not yet been reached.
Brady said he thought it was likely May would win any confidence vote, making her immune to another challenge for 12 months under the party's rules.
Mark Francois, one lawmaker who has submitted a letter, said he expected some colleagues were taking soundings from local party members in their constituencies over the weekend before deciding whether to submit a letter.
At the centre of concerns over the deal is the Northern Irish backstop, an insurance policy to avoid a return to border checks between the British province and EU-member Ireland.
Critics say it would leave Britain bound to the EU in perpetuity and risks dividing the United Kingdom by aligning Northern Ireland more closely with the EU's customs rules and production standards than mainland Britain.
They are also unhappy that this arrangement, although temporary, will form the basis on which arrangements for the future relationship between the EU and the UK are built.
The pro-Brexit ERG group of Conservative members of parliament published its assessment of the deal on Sunday, saying it would leave Britain "half in and half out" of the EU.
The DUP, a small Northern Irish party which props up May's minority government, has threatened to pull its support if the backstop means the province is treated differently from the rest of the United Kingdom.
DUP deputy leader Nigel Dodds said on Sunday it was "time to work for a better deal which does not undermine the integrity of the United Kingdom".
May said negotiations were continuing and she intended to go to Brussels and meet European Commission President Jean-Claude Juncker. She said she would also be speaking to other EU leaders ahead of an EU summit to discuss the deal on November 25.
"We won’t agree the leaving part, the withdrawal agreement, until we have got what we want in the future relationship because these two go together. The focus this week will be on the future relationship," she told Sky. "It is the future relationship that delivers on the Brexit vote."
Several British newspapers reported that five senior pro-Brexit ministers were working together to pressure May to change the deal, but writing in the Sun on Sunday newspaper May said she saw no alternative plan on the table.
Former Brexit minister Dominic Raab, who resigned on Thursday in protest at the deal, said he supported May as leader but her deal was "fatally flawed" and she must change course.
"I still think a deal could be done but it is very late in the day now and we need to change course," Raab told the BBC. "The biggest risk of no deal is taking a bad deal to the House of Commons ... it is very important to take the action now."
Opposition Labour leader Jeremy Corbyn said his party would vote against May's deal when it came to parliament and the government should go back to Brussels for further negotiations. He said that was a priority ahead of pushing for a so-called people's vote on the final agreement."It's an option for the future, but it's not an option for today, because if we had a referendum tomorrow, what's it going to be on? What's the question going to be?" Corbyn told Sky News