Prime Minister Theresa May will meet with EU leaders on Sunday in Brussels to try and drum up support for her Brexit deal.
European Council president Donald Tusk has written to recommend the deal is approved, after the UK agreed to conditions set out by Spain over the future of Gibraltar.
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Spanish Prime Minister Pedro Sanchez threatened to "veto" the summit if assurances were not provided that Gibraltar would be dealt with separately to the UK’s post-Brexit relationship with the EU.
Spain wanted Gilbraltar to be a bilateral issue between London and Madrid, rather than the EU and the UK.
On Saturday, Mrs May agreed to the demands, with the British ambassador to the EU, Sir Tim Barrow, writing to state that a future trade deal may not cover Gibraltar.
Divisions in parliament
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But Mrs May is still facing considerable opposition at home.
The draft deal, which would see the UK enter a 21-month transition period after leaving on March 29 2019 in which it would still be subject to EU rules, has faced opposition from several MPs, including former Brexit secretary Dominic Raab and former work and pensions secretary Esther McVey, who resigned.
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Jacob Rees-Mogg, chair of the European Research Group, has also opposed it, and is one of the MPs to have handed in a letter of no confidence in Theresa May.
The ERG have previously called for a Canada-style deal.
Owen Paterson MP has called it "really unpopular right across the House of Commons".
Party leaders have also come out against it.
Jeremy Corbyn has described the deal as “26 pages of waffle - this empty document could have been written two years ago. It’s peppered with phrases such as ‘the party will look at…’ what on earth has the government been doing for the last two years?”
Scottish First Minister Nicola Sturgeon has echoed his concern that few specific points have been agreed, saying: “I've seen today the current draft - it's not binding, it doesn't have legal effect and effectively it amounts to the House of Commons being asked to vote to exit the EU without knowing what comes next.
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"That's asking people to take a blindfold leap off a cliff edge and I have said all along I just don't think that's a reasonable or acceptable thing to do."
The DUP, which props up the Conservatives in government, has threatened to rethink its support over the deal, with deputy leader Nigel Dodds telling the party’s conference this weekend that the government needs to “bin the backstop”.
The DUP has said it plans to vote against the deal.