French President Emmanuel Macron has vowed to force Britain into the Irish border backstop if it does not give up access to UK fishing waters.

Mr Macron said maintaining the customs union would be used as 'leverage' in the next phase of talks on the final UK-EU trade deal.

Prime Minister Theresa May has insisted Britain will leave the customs union, which is essential to striking trade deals, after Brexit.

But under the divorce deal agreed in Brussels today this can only happen if there is an alternative for keeping open the Irish border.

If France refuses to agree a trade deal because of a dispute over fishing, entering the backstop - which is hated by Brexiteers, Unionists and the DUP - could be inevitable.

Mr Macron's intervention sparked a ferocious backlash from both sides of the Brexit divide.

French President Emmanuel Macron (pictured today in Brussels) has vowed to force Britain into the Irish border backstop if it does not give up access to UK fishing waters

The French President made his inflammatory remarks during his press conference at the end of today's summit in Brussels

Mr Macron (pictured right today with other EU leaders including the Austrian Chancellor Sebastian Kurz, left) has vowed the EU will take a tough line on fishing in trade talks

At a press conference in Brussels today, Mr Macron said: 'An agreement assumes that each side promotes its position.

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. December 13-14: The next EU summit. If the deal has been rejected by MPs, Mrs May could use this to try and secure new concessions. January 2019: 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. Advertisement

'We as 27 have a clear position on fair competition, on fish, on the subject of the EU's regulatory autonomy, and that forms part of our lines for the future relationship talks, which is a lever, because it is in our mutual interest to have this future relationship.

'I can't imagine that the desire of Theresa May or her supporters is to remain for the long term in a customs union, but to define a proper future relationship which resolves this problem.'

He added: 'It is leverage because it is important as to our future relationship and I do not understand that Mrs May and those who support her very much wanted to stay in the Customs Union, they would rather favour new rules.' '

A joint EU statement set out how fisheries was a 'priority' in the next phase of talks.

It said: 'A fisheries agreement is a priority issue, and should be based on principles of reciprocal access and existing quotas.'

A future fisheries agreement 'must be concluded well before the end of the transition period' after Brexit, which should last until the end of 2020 but may be extended for up to two years, the statement said.

'For us access to British waters is a priority,' said a source close to French President Emmanuel Macron.

Brexiteer Ross Thomson said: 'There can be no ifs and no buts on returning full sovereignty over our waters.

'We must decide who fishes in our waters, when they fish and what they fish. Fishing is still a clear red line for me which is why I cannot support the PM’s deal.'

Prime Minister Theresa May (pictured today in Brussels) has insisted Britain will leave the customs union, which is essential to striking trade deals, after Brexit

British fishermen (including at Brixham Harbour, pictured) have been promised UK control of fishing waters after Brexit

Remain supporter Sarah Wollaston said: 'So many false promises were made to the fishing community by Brexiteers.

'Future Framework spells out the Brexit reality that access & quotas will be “in the context of the overall economic partnership”.

'This is not what fisherman were led to expect.'

Scotland's First Minister Nicola Sturgeon said the EU position could not be 'squared' with promises made by Scottish Tories to fishing communities.

The divorce agreement approved by EU leaders on Sunday assures that European fishermen will retain access to British territorial waters during the transition period.

During the transition, Britain will continue to apply EU rules and contribute to its budget, but without participating in its decision-making.

Scottish Tory Brexiteer Ross Thomson said: 'There can be no ifs and no buts on returning full sovereignty over our waters'

Remain supporter Sarah Wollaston said: 'So many false promises were made to the fishing community by Brexiteers'

Scotland's First Minister Nicola Sturgeon said the EU position could not be 'squared' with promises made by Scottish Tories to fishing communities

May tells MPs it is their 'DUTY' to back Brexit deal because constituents' jobs depend on it as she vows to fight 'with all my heart' in Commons as Juncker warns it's 'only deal possible'

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.

Theresa May promised the country she will fight 'with all my heart' to get her divorce through the Commons as she held a press conference to close a landmark day in Brussels (pictured)

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.

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. Advertisement

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'.

Jean-Claude Juncker (left at a press conference with Donald Tusk and Michel Barnier today) warned MPs the Brexit divorce is the 'only deal possible' today as Brussels signed off on the plans at an historic summit

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.

German Chancellor Angela Merkel (pictured today in Brussels) was among the EU leaders who voted for the Brexit deal today

Theresa May sat alongside Donald Tusk at today's historic summit (pictured) to finalise the terms of Britain's divorce ahead of the crucial Commons 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.'