The latest round of talks between the UK and European Union have broken up early, with “significant differences” still remaining between the two sides, Boris Johnson’s Europe adviser David Frost said.
Talks in Brussels between Mr Frost’s team and the EU side led by Michel Barnier were due to continue into Friday.
Mr Frost said: “We have completed our discussion of the full range of issues in the negotiation in just over three days.
"Our talks were face-to-face for the first time since March and this has given extra depth and flexibility to our discussions.
“The negotiations have been comprehensive and useful. But they have also underlined the significant differences that still remain between us on a number of important issues.”
He said talks will continue next week in London.
Mr Barnier said in a statement that after four days of discussions "serious divergences" remain.
"The EU side had listened carefully to UK Prime Minister Boris Johnson's statements in recent weeks, in particular, his request to reach a political agreement quickly, and his red lines: no role for the European Court of Justice in the UK; no obligation for the UK to continue to be bound by EU law; and an agreement on fisheries that shows Brexit makes a real difference," said Mr Barnier.
"The EU engaged constructively, as we had already done during the fourth round of negotiations in June."
He added that there will be no economic partnership without guarantees for a level playing field, a sustainable and long term solution for European fishermen and women and an "overarching institutional framework and effective dispute settlement mechanisms".
It is hoped that the Brexit talks will result in a deal which could be implemented before the current post-Brexit arrangements expire at the end of the year.
The Prime Minister’s spokesman said that UK-EU negotiations need to end "by the autumn" and the job of the UK’s chief negotiator will “cease to exist” later this year.
But recently German Chancellor Angela Merkel told the German parliament that although talks between the UK and EU were intensifying the EU “must be prepared” for the possibility that a deal will not be reached.
It comes as Germany assumes the rotating EU Council presidency for the next six months, giving the chancellor an influential role in the final phase of the Brexit process.
In a sign of the strained relations between the two sides, the UK failed to meet a deadline for submitting equivalence assessments on financial services regulations.
These could help determine the City’s access to European markets and vice versa.
Whitehall sources suggested that the demands made by the EU in 1,000 pages of questionnaires were “much broader than the equivalence criteria set out in legislation”.
The UK has insisted that it wanted to “work constructively” with the EU.
The Prime Minister’s official spokesman said: “We believe that there is a free trade agreement to be reached but we have also been very clear that we will be prepared for either eventuality at the end of the year, whether that be a free trade agreement or having a trading relationship based on the same terms that Australia currently has.”