Theresa May faces a grilling from MPs later over the draft Brexit agreement the UK has reached with the EU.
The PM secured her cabinet’s backing for the deal after a five-hour meeting, although several ministers are understood to have spoken against it.
She has also faced a backlash from Tory Brexiteers and her Democratic Unionist Party (DUP) backers, amid suggestions of moves to force a no-confidence vote.
Labour will announce later whether or not it will back the deal.
However, leader Jeremy Corbyn said he did not believe the agreement – set out in a 585-page document – was in the national interest.
She emerged from the marathon cabinet meeting on Wednesday evening and declared the choice before the UK to be clear.
“This deal, which delivers on the vote of the referendum, which brings back control of our money, laws and borders, ends free movement, protects jobs, security and our Union; or leave with no deal, or no Brexit at all.”
The EU said the agreement marked “decisive progress”, clearing the way for a special summit of EU leaders to approve it.
However, Brexiteer MPs were angered by a “backstop” provision allowing the creation of a temporary “EU-UK single customs territory” to prevent border checks in Ireland in the event no trade deal is in place.
Assuming she survives in post, Mrs May will face a battle to get the agreement through the House of Commons ahead of the UK’s exit from the EU on 29 March.
She held talks with Labour leader Jeremy Corbyn, DUP leader Arlene Foster and Scotland’s First Minister Nicola Sturgeon on Wednesday evening.
What’s been agreed?
A draft agreement on the UK’s withdrawal from the EU, and a statement setting out what the two sides want their future relationship to look like.
Northern Ireland would also stay aligned to some other EU rules, so that checks on things like agricultural products and goods standards were not needed.
The EU said this was “indispensable” to avoiding a hard border. But it is proving controversial.
Brexiteers are angry about the prospect of being tied to EU customs rules long-term, particularly as the arrangement could only be terminated by mutual consent of Brussels and London.
Meanwhile, the DUP has said it will not tolerate anything that creates a new border down the Irish sea.
Both sides have resolved to ensure the backstop is not necessary by coming up with alternative arrangements.
DUP leader Arlene Foster described her meeting with Mrs May as “frank”.
“She is fully aware of our position and concerns,” she tweeted.
Ms Sturgeon said Scotland was not mentioned in the agreement which she said “disregards our interests, and puts Scotland at a serious competitive disadvantage”.
Irish Taoiseach Leo Varadkar praised Mrs May for “honouring her promise” to prevent a hard border.
He said Wednesday had been “one of the better days in politics”, and avoiding a hard border had been “one of the most difficult challenges” of the process.
From the pro-European side of the debate, the Best for Britain campaign said Mrs May had “sacrificed the national interest in favour of her own preservation”.
The Confederation of British Industry (CBI) said the agreement was “progress” as it moved the UK “one step away from the nightmare precipice of no deal”, while the Freight Transport Association and the National Farmers’ Union also welcomed the publication.