Boris Johnson has sparked fresh hostilities with Brussels, by claiming the EU’s approach to the Brexit negotiations fails its own legal duty.

The Foreign Secretary claimed the EU is obliged to bow to British pressure to start talking about a future trade deal – just days after EU leaders again insisted the “divorce” must be settled first.

Michel Barnier, the EU’s chief negotiator, together with leaders of the European Parliament, poured cold water on trade talks starting next month, as originally hoped.

They pinned the blame on Britain’s failure to make the necessary “sufficient progress” on a financial settlement for Brexit, on citizens’ rights and on the border in Ireland.

Before a meeting with his EU counterparts in Tallinn, Estonia, Mr Johnson first said he had “absolutely rock-solid confidence” that a deal would be reached before Britain’s exit in March 2019.

But he went further, saying: “Article 50 makes it very clear that the discussion about the exit for a country must be taken in the context of a discussion of the future arrangements, and that’s what we are going to do.”

The claim came despite David Davis, the Brexit Secretary, publicly accepting, in July, that the EU had a right to expect the divorce settlement to be discussed first.

Mr Johnson spoke at the end of a bruising week in UK-EU relations, in which a former European Council president, Herman van Rompuy, put the chances of trade talks beginning in October as “in the neighbourhood of zero”.

The leak of Home Office plans for the UK to limit the free movement of people from day one after Brexit appeared to throw fresh obstacles in the way of a transitional deal, to cushion the impact of Brexit.

Meanwhile, Mr Barnier rejected the UK’s suggestions for a light-touch Irish border after withdrawal, suggesting they presented a threat to the integrity of the single market.

A position paper published by the European Commission set out how, as the problem was of the UK’s making, it was the UK’s responsibility to come up with a “unique solution”.

However, Mr Johnson told reporters that a solution to the problem of the Irish border would be found between the negotiating parties and made light of the EU’s fears.

“I think we can all work together to come up with a solution to that one,” he said.

“It is not beyond the wit of man. We have had a common travel area between the north and south of Ireland for getting on for a century. We are going to continue to make that work.”

In Brussels, there is also growing anger at Theresa May’s decision to reject an invitation to address the European Parliament to try to convince MEPs of her vision for future relations.

Crucially, the European Parliament has the right to veto any agreement between the EU and the UK.