MICHEL Barnier has warned Boris Johnson his latest ideas on Brexit are “unacceptable” and it is “difficult to see” how they could be the basis of a deal.

Speaking after meeting Germany’s foreign minister in Berlin, the EU’s chief negotiator said the UK was still not close to a workable alternative to the Irish backstop, suggesting agreement before October 31 remains a faint hope.

On his way to New York for the UN climate summit, Mr Johnson said he was “cautiously optimistic” of persuading the EU27 to back his plans before their key summit on October 17.

But Mr Barnier said the UK’s proposals for a regulatory and customs land border on Ireland required the EU to change the way its internal market and border controls operated.

“This is unacceptable. My mandate is clear of the 27 leaders, the EU and the European parliament, safeguarding peace and stability in Ireland and protecting the integrity of the single market,” he said.

“Let me therefore put it clearly that based on current UK thinking, it is difficult to see how we arrive at a legally operable solution that fulfils all the objectives of the backstop.”

He said the EU-UK talks were now in a “very difficult sensitive phase”, adding: “The ball is in the court of the British.”

Mr Johnson said he would tell Donald Trump “the NHS is not on the table” in any post-Brexit trade deal when he meets him in New York.

The PM is also due to meet European Council president Donald Tusk and Taoiseach Leo Varadkar.