- Video report by ITV News Europe Editor James Mates
Theresa May has arrived in Brussels for talks with the European Commission president Jean-Claude Juncker as both sides attempt to finalise the Brexit deal before the EU summit on Sunday.
The prime minister is under pressure from Tory Brexiteers to secure further concessions from the EU in the meeting with the bloc's top official.
But Mrs May's position has been strengthened after members of the pro-Brexit European Research Group failed to gather enough support to topple her as leader.
This small victory for Mrs May in a week of turmoil came amid mounting evidence of tensions between the prime minister and the Democratic Unionist Party over the Brexit deal.
Mrs May had earlier warned that voting down her Brexit deal in Parliament "could risk no Brexit at all".
Mrs May's proposed deal with Brussels was the subject of numerous thorny exchanges at Prime Minister's Questions - both from Labour leader Jeremy Corbyn and her own backbenches.
Many want changes to the Northern Irish backstop contained in the Brexit divorce agreement, making it clear how the UK can exit the controversial arrangement.
A special EU Brexit summit is due to take place on Sunday at which the remaining 27 member states are expected to approve her plan.
It would still need Parliamentary approval and with many Conservatives, as well as the 10 DUP MPs who prop up Mrs May's administration in the Commons, threatening to vote down her deal, the prime minister has repeatedly warned the alternative is a damaging no-deal Brexit.
But following earlier comments by Work and Pensions Secretary Amber Rudd that no-deal would be prevented by Parliament, Mrs May told the Commons: "The point that has been made by a number of my colleagues in relation to the vote that will come before this House on a meaningful vote on a deal from the European Union is very simple.
"If you look at the alternative to having that vote with the European Union it will either be more uncertainty, more division or it could risk no Brexit at all."
However, pressed by Esther McVey, who quit as Work and Pensions Secretary over the Brexit deal, whether the UK would leave the EU in March 2019 come what may, Mrs May assured her it would.
Mr Corbyn labelled the deal a "failure" and told the Commons: "It fails the prime minister's red lines, fails Labour's six tests, and it fails to impress the new Northern Ireland minister (John Penrose), who just hours before he was appointed said the deal is 'dead'.
"Instead of giving confidence to the millions of people who voted both Leave and Remain, this half-baked deal fails to give any hope that it can bring the country together again.
"Isn't it the case that Parliament will rightly reject this bad deal, and if the Government can't negotiate an alternative then it should make way for those who can and will."
Mrs May replied: "He is opposing a deal he hasn't read, he's promising a deal he can't negotiate, he's telling Leave voters one thing and Remain voters another - whatever (Mr Corbyn) will do, I will act in the national interest."
The prime minister appears to have averted an immediate challenge to her position from Tory critics, with the attempt to force a vote of no confidence so far failing to win enough support to force a showdown.
But several Tory MPs raised concerns about the deal in the Commons.
Brexiteer Andrew Rosindell said he was "deeply unhappy" with the withdrawal agreement, adding: "Will she now even at this late stage, please think again and instead lead our country in a new direction completely cutting away the tentacles of the EU over our cherished island nation once and for all?"
Mrs May responded saying her deal delivered on the promises of Brexit and ensured a continued close trading relationship with the EU.
Mrs May said the UK would not walk away without paying its debts.
She said: "In relation to the £39 billion, which I would remind him is significantly less than the £100 billion the EU were first talking about us needing to pay, these are about the legal obligations the UK has."