BRUSSELS/PARIS (Reuters) - France on Thursday led calls among European Union states for changes to the draft agreement on Britain’s exit from the bloc, adding to uncertainty over the fate of the deal as British Prime Minister Theresa faced an uproar at home.

FILE PHOTO: Fishermen work on the French trawlerThierisa during the start of the scallop fishing season off Port-en-Bessin, France, October 1, 2018. REUTERS/Pascal Rossignol/File Photo

May’s cabinet on Wednesday endorsed the draft to end Britain’s four decades in the bloc, a nearly 600-page, dense legal text that is far from certain to pass in the UK parliament and prompted several British ministers to resign on Thursday.

The other 27 EU states staying on together after Brexit plan to rubber-stamp the draft at a Nov. 25 leaders’ summit. But France spearheaded a group of states in raising objections to what has so far been agreed on fishing between the EU and UK after Brexit, diplomatic sources and EU officials said.

“On the draft agreement, several member states will ask for improvements on fishing,” a diplomatic source close to the negotiations said, listing concern about the issue in France, Denmark, Spain, Portugal and the Netherlands.

Finland and Ireland were also worried about future fishing arrangements, other diplomatic sources told Reuters.

Britain’s rich fishing waters are currently available to other EU states under mutual access arrangements with set quotas. While the EU has wanted to safeguard that scheme after Brexit, Britain wants to take unilateral control of its waters.

In the end, the draft Brexit deal leaves the case without a firm resolution at this stage. It says the two sides would try to agree on the future of fisheries by July 2020, during the transition period after Brexit, to form part of an eventual new EU-UK trade deal.

The draft leaves fisheries outside of the single EU-UK customs zone that could be triggered if the sides find no other way to ensure an open Irish border - the so-called “backstop” mechanism that has long held up an overall deal.[nL8N1XP9TA]

“Not all member states were very happy with that,” an EU official said, adding that it would not be easy to agree on the future fishing schemes.

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Conceding access to its waters was highly disputed around the time Britain joined the then-European Community in 1973.

Territorial clashes between French and British fishermen have flared sporadically in the past decades, most recently last August when French vessels rammed British trawlers off the coast of Normandy in the so-called “Scallop Wars”.

A separate political declaration on future relations between the EU and UK - which forms a package with Britain’s withdrawal agreement but has no legal authority - says the two sides should also take conservation into account in their future fish deal.

CAN IT GET ANY BETTER?

Some other EU diplomats, however, expressed doubt that the bloc would bring down the whole deal over fisheries.

They said France’s opposition was tactical and that member states concerned with fisheries could still seek more reassurances in the declaration on future ties - which is now being discussed among the 27 member states - rather than demand changes to Britain’s formal withdrawal deal.

The draft agreement has infuriated hardline eurosceptics in May’s Conservative Party and the Northern Irish party that props up her minority government by tying the country’s economy closely to the EU for years ahead and hence potentially limiting Britain’s scope to forge its own trade deals around the world.

As May’s critics at home cried betrayal, the EU side has said that was the best agreement possible given the existing red lines from both sides, namely that May’s government decided to leave both the EU’s customs union and single market through Brexit while keeping open the border between Britain’s Northern Ireland province and EU member state Ireland.

The EU official suggested the draft deal could not be improved without a considerable change in this basic approach. “We think we have on both sides exhausted the margin for maneuver under our respective mandates,” the person said.

Some other sources in Brussels, however, stressed more negotiations could not be ruled out as the political situation in Britain was changing by the hour.