Major persistent "divergences" are dogging talks between the EU and Britain meant to work out a post-Brexit relationship, the chief negotiators from both sides said Wednesday.

The downbeat assessment, tweeted separately by the EU's Michel Barnier and Britain's David Frost, cast a pall over efforts to strike a deal within the next few days, before the negotiating window closes.

Any accord needs to be swiftly arrived at and then ratified before a post-Brexit transition period finishes at the end of next month.

Barnier said the EU "is prepared for all scenarios" while Frost said solutions needed to "fully respect UK sovereignty".

Barnier said that "very serious divergences remained" on the three sticking points that have dogged the negotiations from the start: agreeing a framework to ensure fair trade competition; coming up with a robust disputes mechanism; and satisfying the EU's demand of retaining fishing access to some British waters.

Any accord needs to be swiftly arrived at and then ratified before a post-Brexit transition period finishes at the end of next month
Any accord needs to be swiftly arrived at and then ratified before a post-Brexit transition period finishes at the end of next month AFP / Justin TALLIS

"These are essential conditions for any economic partnership," Barnier said.

The EU negotiator issued his tweet after briefing EU member state envoys and the European Parliament on the state of play after hosting Frost in Brussels this week for a face-to-face session of talks.

Frost, in his tweet, said the two sides have "just finished two weeks of intensive talks" but "I agree with Michel Barnier that wide divergences remain on some core issues".

The two sides were to maintain contact through videolinks in the coming days and were expected to then resume a last-push face-to-face round in London next week.

EU diplomats confirmed the impasse, with one saying that "I think Barnier's tweet gives a very blunt picture that matches his message to the (EU) ambassadors".

Another diplomat said: ""Brexit talks seem to have made some progress lately. Unfortunately the UK does not seem to be engaging sufficiently on key issues like level playing field, governance and fisheries. Given this situation a no-deal outcome still can't be excluded."

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