Theresa May told MPs to do their 'duty' and vote for the Brexit deal as she promised she will fight 'with all my heart' to get it through the Commons.
After an historic Brussels summit to seal the deal, the Prime Minister said the deal took back control of 'our laws, borders and money' while protecting jobs and security - meaning it was in the 'national interest'.
At a press conference to mark the landmark day on the road to Brexit, Mrs May began a two week battle to persuade fractious MPs the deal was the best available - but the PM's hopes look bleak.
Mrs May told her MPs: 'I think we have a duty as a Parliament ... to deliver Brexit.'
The Prime Minister repeated her vow to never allow a second referendum on Brexit while she is No 10 - but again swerved questions about whether she will quit if her deal is voted down in Parliament.
Echoing the leadership of the EU, Mrs May insisted that what she was bringing home was the 'best deal possible' and warned her rebels that voting no would 'open the door to even more division and uncertainty'.
She said: 'Crucially it is a deal that delivers on the vote. I think this is so important to me: the people voted for Brexit ... it's, in a sense, a duty for their politicians, who asked them to make that choice, to then deliver on that choice.'
EU Commission President Jean-Claude Juncker warned MPs the Brexit divorce is the 'only deal possible' today as Brussels signed off on the plans. Effectively telling MPs to take it or leave it, Mr Juncker used his press conference to underline Mrs May's fight in the Commons.
Mr Juncker said anyone hoping to vote down the deal and get a better deal 'will be disappointed', while EU leaders put on a united front to insist there was nothing else on the table.
EU Council President Donald Tusk insisted Britain and the EU would 'remain friends until the end of days and one day longer' as the bloc agreed the terms of its first ever exit.
The 27 national leaders met for just 40 minutes today to rubber stamp both the divorce deal and the political declaration outlining a future trade deal. They claimed Brexit is a 'tragedy' and 'not a moment for celebration'.
The divorce documents have triggered a furious row in the UK and an attempt to oust Mrs May but the EU's negotiator Michel Barnier insisted MPs must 'take responsibility' and vote the deal today.
He said that after 20-months of painstaking talks, the controversial divorce deal had to be agreed as the basis for rebuilding trust between Britain and Europe.
Mrs May's troubles have been escalated by a row over Gibraltar as she was forced to hand Spain the chance to claim a victory over the Rock. Spain's PM Pedro Sanchez claimed today 'we all lose with Brexit but Spain wins on Gibraltar'.
As she begins her new battle, Mrs May's hopes of winning the Commons vote in around two weeks look bleak. The package is opposed by more than 90 of her own MPs, her DUP allies and the Opposition Labour Party.
The Prime Minister has vowed to take her deal out to the country in a bid to persuade MPs but since it was published opposition has mounted rather than diminished.
The DUP hinted today at backing for an alternative deal while former PM Tony Blair insisted the widespread loathing of the package fuelled demands for a new public vote.
Following today's summit, speaking on his LBC show, Nigel Farage condemned the deal.
He said: 'I've decided on balance, no. I'm going to vote against it.'
'This deal is an absolute disaster,' he said.
'It's a betrayal of everything we voted for in Brexit and if the risk was that the other side could force us to vote again, right now I think that risk is worth it.'
Labour leader Jeremy Corbyn said: 'This is a bad deal for the country.
'It is the result of a miserable failure of negotiation that leaves us with the worst of all worlds. It gives us less say over our future, and puts jobs and living standards at risk.
'That is why Labour will oppose this deal in Parliament. We will work with others to block a no-deal outcome, and ensure that Labour's alternative plan for a sensible deal to bring the country together is on the table.
Foreign Secretary Jeremy Hunt admitted Mrs May could be doomed if she was defeated.
Pressed by the BBC's Andrew Marr on whether the Government could collapse, he said: 'It's not possible to rule out anything.'
As the summit convened today Mr Barnier said: 'Now it is time for everybody to take their responsibility.
'This is a necessary step to build trust between the UK and EU.'
What has been agreed in Brussels today?
The Brexit deal comes in two parts, both of which were signed off in Brussels today:
The Withdrawal Agreement
is a 585-page legal text that sets out the terms of the UK's departure.
Among its contents are arrangements for the contentious Northern Ireland backstop and the £39 billion 'divorce bill'.
It is a full blown treaty which must be written into both UK and EU law to a apply.
There is also a political declaration
agreed between Britain and the EU.
The 26-page document sets out a framework for the future relationship between the UK and the EU.
It outlines a spectrum of possible trade deals and what each option might mean. The final deal will be subject to years more negotiation in Brussels.
Austrian Chancellor Sebastian Kurz says: 'It is important that everyone in the UK is aware of the fact that this agreement is the final result. It will definitely not be renegotiated and there will be no further leeway.'
Earlier in the day, Mr Juncker said the EU's position would not change its 'fundamental position' and predicted the Commons would eventually endorse the deal insisting it was the 'best deal that could be achieved'.
He said today's events were a 'tragedy' and a 'sad day' as the bloc finalised the first ever exit of a member.
France's President Emmanuel Macron arrived insisting it was 'not a day for celebration' and said it showed the need for the EU to reform.
Dutch Prime Minister Mark Rutte warned the EU could not offer 'anything more' if the Commons votes down the deal as he arrived at the summit.
He said this is the 'this is the max we can all do' and warned: 'Nobody's winning - we are all losing.'
Lithuania's president predicted Dalia Grybauskaite 'anything could happen' if the deal is voted down in the Commons, including a new referendum.
When she arrives later, Mrs May will be more upbeat, insisting the two part agreement is the right one for Britain as she faces a bigger battle to make the case at home.
She wrote an open letter to the British public today appealing for support for her deal, insisting it meant a 'brighter future' for the country.
Despite her positive tone, the Prime Minister faces an uphill battle in the run-up to the Commons vote in around two weeks time.
What happens now the Brexit deal has been signed off in Brussels?
Brexit passed a major milestone in Brussels today as EU leaders agreed the negotiated divorce deal.
This is what the next steps are:
Tomorrow, November 26:
Theresa May will make statement to MPs on the summit and launch her push to win the 'meaningful vote' on the deal. She can expect another furious response from MPs.
Around December 11:
The meaningful vote itself. This is the absolutely crucial moment and could make or break the Prime Minister and her deal. MPs will vote after a debate that could last as long as five days.
If the vote carries, Mrs May survives and Brexit is on track as she plans. If she loses, she could resign.
The next EU summit. If the deal has been rejected by MPs, Mrs May could use this to try and secure new concessions.
The European Parliament is due to vote on the deal - but will only do so if it has been agreed in the House of Commons.
March 29, 2019:
Exit day. This is written in law so unless there is a dramatic shift Britain will leave the EU, deal or no deal.
Arlene Foster, the leader of the DUP propping up the Tories in Government, said there were 'no circumstances' she would order her 10 MPs to vote for the deal.
And Mrs Foster dangled Mrs May's political mortality in front of her insisting if she managed to force the deal through, the DUP would 'review' the confidence and supply deal keeping her in No 10.
Insisting the deal was likely to fail anyway, Mrs Foster told the BBC's Andrew Marr: 'Why waste time? Why not look for a better deal now?'
Asked if Mrs May had broken promises on the Union, Mrs Foster said: 'This deal goes against everything she has said around all of that.'
Former Tory leader Iain Duncan Smith - who Mrs May had hoped to win round - doubled down on his opposition today, insisting the deal does not deliver Brexit.
He told Sky News's Sophy Ridge on Sunday: 'I don't believe that, so far, this deal delivers on what the British people really voted for, take back control of your borders, your laws, your money. I think it has ceded too much control.
'I believe the Government needs to go back and say things like 'the backstop, we simply cannot agree it and you must take all of that reference out' and things to do with the Court of Justice.
'That would make this a better deal, but right now the balance is definitely tilted against this being a deal, I'm afraid, that delivers on what the Government said they would deliver.'
In another blow for Mrs May, Labour MP Lisa Nandy - who had hinted she would vote for the deal on behalf of her Brexit supporting Wigan constituency - confirmed she would vote no.
She told Sky News: 'It's inconceivable that I'll be voting for it - I won't be voting for the withdrawal agreement.'
A final breakthrough yesterday paved the way for today's summit when Spain dropped its threat to vote against the deal.
Ministers 'draw up secret Plan B' in case May's deal is rejected in Commons vote
Ministers are making a secret 'Plan B' for Brexit if Mrs May's deal is rejected in the Commons, it was claimed last night.
The PM faces an uphill task to win over Brexiteer MPs, many of whom are furious about the withdrawal agreement and in particular the Irish backstop.
Her DUP allies are also poised to desert her in the showdown vote.
The backup plan being formulated by ministers would be a 'Norway option' in which Britain stays in the European Economic Area, the Sunday Telegraph reported.
Sources said the plan would give the UK a more definite exit procedure from EU rules.
Such a mechanism would appease Brexiteer fears that the current deal would tie Britain to Brussels rules indefinitely.
However, the Norway option would reportedly not allow an end to free movement of people.
Madrid claimed Mrs May had caved in to demands to take Gibraltar out of UK-EU trade talks.
The PM insisted the UK's position on Gibraltar had not changed, saying she would always 'stand by' its citizens, while the territory's chief minister denied that Spain had secured new guarantees.
The agreement means Mrs May will take the completed deal back to Westminster for a Commons vote, expected early next month.
With a battle looming to win over Brexiteer MPs, Boris Johnson yesterday fired up the DUP - which has propped up Mrs May's government but is set to vote against her - with a pot-stirring speech in which he savaged the PM's 'humiliating' deal.
It has been claimed today that ministers are making 'Plan B' proposals for a new Brexit deal if Mrs May's agreement is rejected by Parliament.
As EU leaders arrived, Lithuanian President Dalia Grybauskaite predicted there could still be an 11th hour reversal after today's summit.
She said: 'Everything could happen, at least four possible scenarios could be in place, but it's up to the British side to decide what path to choose.
'It could be a second vote of the people, it could be new elections, it could be a request for renegotiations, there is at least four scenarios, I calculate.'
Spanish PM Pedro Sanchez earlier withdrew his threat to boycott the EU summit and said Spain will vote in favour of Brexit after clinching a last-minute deal on Gibraltar.
The row over the British territory at the southern tip of Spain had threatened to derail the Brexit deal.
Madrid has insisted on keeping the issue under its control in bilateral talks with London rather than leaving Brussels to decide its future in a UK-EU trade deal.
Mr Sanchez announced that Brussels and the UK had 'accepted Spain's demands', providing Madrid with what was described in Spanish media as 'triple protection'.
The triple shield is said to consist of guarantees from EU bosses Juncker and Tusk; the 27 remaining member states; and the UK, according to The Local
'I have just announced to the King that Spain has reached an agreement on Gibraltar,' Mr Sanchez told a news conference.
'The European Council will therefore be held tomorrow. Spain has lifted the veto and will vote in favour of Brexit.'
Madrid's foreign minister Josep Borrell went further, saying the agreement is 'highly positive for Spain' and 'the most important' since the Treaty of Utrecht in 1713 under which Gibraltar was ceded to the UK.
Britain has agreed that bilateral talks will continue with Spain on the future of Gibraltar.
But Mrs May and Gibraltar's chief minister Fabian Picardo cast doubt on Madrid's claim it had won new guarantees.
Speaking in Brussels Mrs May said: 'We have worked through the withdrawal issues for Gibraltar with Spain in a constructive and sensible way.
'We have ensured that Gibraltar is covered by the whole Withdrawal Agreement and by the implementation period and we will always negotiate on behalf of the whole UK family, including Gibraltar, and in the future relationship we will stand up for their interests.
'The UK's position on the sovereignty of Gibraltar has not changed and will not change. I am proud that Gibraltar is British and I will always stand by Gibraltar.'
Mr Picardo said: 'What you have heard from the Spanish Prime Minister today was not a reflection of any new position, however much he tried to present it as such.
'Pedro Sanchez has achieved no guarantees whatsoever in respect of the future of Gibraltar.
'But I can guarantee Pedro Sanchez one thing in respect of the future of Gibraltar: It is an entirely British future that will suffer no dilution.
As Mr Sanchez was speaking, European Council president Mr Tusk issued a letter inviting leaders of EU member states to approve the deal at Sunday's summit.
'I will recommend that on Sunday we approve the outcome of the Brexit negotiations,' he said, saying the deal on the table reduces 'the risks and losses resulting from the United Kingdom's withdrawal.'
He said: 'Although no-one will have reasons to be happy on that day, there is one thing I would like to stress: at this critical time, the EU27 has passed the test of unity and solidarity.'
Liberal Democrat Brexit spokesman Tom Brake claimed the Prime Minister had 'caved in' and 'appears to have cast the people of Gibraltar aside'.
After battling to an agreement with Brussels Mrs May now faces a fierce battle to steer her deal through the House of Commons.
She has so far survived an attempted coup from Tory backbenchers but a defeat in Parliament could trigger a no-confidence vote or general election.
The Sunday Telegraph reported that ministers are secretly preparing a backup 'Norway option' as an alternative if Mrs May's deal is voted down.
Boris Johnson blasts May's deal at DUP conference
Boris Johnson today spoke at the DUP conference in Belfast to fire up the party faithful in a bid to scupper Theresa May's Brexit plans.
The former foreign secretary warned that the PM was heading for an 'iceberg' and her package would leave Northern Ireland 'ruled by the EU'.
He said Mrs May was giving away the £39billion divorce settlement too easily – suggesting half should be withheld until after a final trade agreement is sealed at the end of 2020.
Mr Johnson said the country was 'on the the verge of making a historic mistake'.
'If we are not careful we are going to stay in the customs union, we are going to stay in the single market, we are going to be rules takers,' he said.
'Unless we junk this backstop, we will find that Brussels has got us exactly where they want us – a satellite state.
But Mr Johnson again stopped short of calling for Mrs May to be ousted today, despite dozens of other Eurosceptics putting in no-confidence letters.
That deal would reportedly create a more definite exit mechanism from EU rules, but would not allow an end to free movement.
In a sign of the trouble she faces, her former Foreign Secretary Boris Johnson spoke at the DUP conference to demand the scrapping of the Irish backstop.
The DUP has propped up Mrs May's government since she lost her majority at last year's election but the alliance has come under strain over the Brexit deal and the party has suggested it will vote against the agreement.
Mr Johnson said yesterday: 'Unless we junk this backstop, we will find that Brussels has got us exactly where they want us - a satellite state.
He warned the draft Brexit deal is in danger of turning Northern Ireland into an 'economic semi-colony' of the EU.
The backstop proposal would see Northern Ireland adopt a different regulatory regime to Great Britain in the event a wider UK-EU trade deal fails to materialise in talks on the future relationship.
DUP leader Arlene Foster told delegates that while she believes Theresa May is 'genuine' in her desire to protect the Union, the draft deal fails to do that.
A Gibraltar housing minister also spoke at the DUP conference demanding that Spain be given no hope of taking away its sovereignty in Brexit talks.
Samantha Sacramento insisted that Gibraltar will not be 'bullied' by any bid from Madrid to undermine its sovereignty.
She was applauded as she told DUP conference delegates in the Crown Plaza Hotel: 'Gibraltar will not fold.
Arlene Foster says May's deal is 'worse than Corbyn in charge'
Arlene Foster has said that Theresa May's Brexit deal is a worse outcome for Britain than a government led by Jeremy Corbyn.
Mrs Foster dismissed claims that the DUP is merely playing a game of brinkmanship and would cave in and support Mrs May if the alternative was a general election and a possible Labour government.
Asked if Mrs May's Brexit is a greater threat than a government led by Jeremy Corbyn, Mrs Foster told the Times: 'I think it is.
'The reason I say that is on day one of us leaving the EU there would be no difference, we would be exactly the same as the rest of the UK but in year five or ten we would be different.
'If people [in Northern Ireland] are looking to Dublin for representation in Europe because we're the subject of EU rules, that is so dangerous in terms of the Union.
'All the things we build the Union on — the economic unit, the cultural, social, political and historical - start to diverge.'
'The Union Jack, our precious Union Jack, is not a mere flag. To those of us who have endured hard times to secure the continuity of our British heritage, our British values and freedoms, the Union Jack encapsulates all we are as a people.'
Ms Sacramento said Gibraltar was committed to making Brexit work, despite the fact that 96 per cent of its citizens voted Remain.
'It is critical that the United Kingdom remains firm in the defence of our right to self-determination and that Spain is given no hope in its campaign to take our sovereignty from us,' she told the DUP faithful.
'Our borders and our history are very different but our solidarity in defence of our democratic right to preserve our British way of life is unshakeable.'
She concluded: 'Gibraltar greatly appreciates the support that the DUP has expressed in support of Gibraltar and its right to remain British and, as my chief minister so often says, we are red, white and blue, we are red, white and proud.'
Prime Minister Theresa May has insisted the proposed EU withdrawal deal is in the interests of 'the whole UK family', including Gibraltar.
The DUP's Nigel Dodds also savaged the deal, saying: 'The DUP wants a deal with the European Union, we understand that businesses, families and communities want certainty.
'But it is not this deal. It is not a deal at any price. The prime minister used to say that. We still say that.
'So Prime Minister, the message from this conference, from every section of this party is - bin the backstop.'
He added: 'In the coming weeks Parliament will be faced with a clear choice on the future of our country.
'To be a free independent trading nation leaving the EU as one United Kingdom or to be locked into an EU straitjacket, divided and diminished.
'The published Withdrawal Agreement portrays a pitiful and pathetic place for the United Kingdom.
'Hundreds of pages are devoted to a backstop which will bind the United Kingdom into taking the rules of the EU with no right to leave and no end date.'
On Thursday Mr Tusk sent a draft of the political declaration to the EU 27 countries.
The document sets out the framework for the future relationship between the UK and the EU.
It has been agreed at negotiators' level and agreed in principle at political level.
The Withdrawal Agreement is the 585-page legal text that sets out the terms of the UK's departure.
Among its contents are arrangements for the contentious Northern Ireland backstop and the £39 billion 'divorce bill'.
The declaration states how trade, security and other issues will work in broader terms.
In an interview with BBC's Emma Barnett on Friday Mrs refused to say if she would quit if she fails to win backing for her deal.
She said the deal would protect jobs and allow Britain to get on with Brexit in March.
But asked repeatedly whether she will resign if she loses in the Commons - as seems inevitable - Mrs May swerved the question to insist: 'No... I'm focusing on ensuring that we get this deal through Parliament.
'I believe this is absolutely the right deal for the UK. This is not about me.'