European leaders on Thursday demanded Britain urgently give ground on fair trade rules to unblock stalled post-Brexit negotiations, angering London and putting the fate of the talks in jeopardy.
The 27 bloc leaders arrived for a summit in Brussels expressing cautious optimism but, in their written conclusions, urged the EU and its member states to step up preparations for a chaotic "no deal" exit.
Their calls for urgency were balanced however by an invitation that Britain keep talking next week in London and in Brussels the week after that.
"As of tomorrow I will be speaking with my counterpart David Frost. On Monday, we'll be in London for the full week, including the weekend if necessary," the EU's chief negotiator Michel Barnier said after addressing the leaders.
"That's what I have proposed to the British team," Barnier said.
The invite comes after a warning by Prime Minister Boris Johnson that he could walk away from the negotiations unless the results of the summit pointed to a breakthrough.
The EU never recognised his deadline and in their conclusions put the onus on Johnson to rescue a deal as time runs out.
In an unusually testy tweet, the UK's Frost said he was "disappointed" by the summit conclusions, underlining that they "no longer committed to working 'intensively' to reach a future partnership" as had been earlier promised.
Frost also scoffed at the EU's charge that only Britain should budge, calling it "an unusual approach to conducting a negotiation".
Johnson would decide his next move on Friday, he said.
- 'Good compromise' -
German Chancellor Angela Merkel appeared to take the criticism on board and after the summit underlined that it was up to the EU to make compromises too.
"We have asked Great Britain to continue to be willing to compromise towards an agreement. Of course, this also means that we have to make compromises," Merkel said.
Tempers flared despite signals that the Europeans seemed to open to moving on one of their hard-held red lines, fishing.
President Emmanuel Macron of France hinted at possible compromise on the thorny issue, saying he was open to finding a "good compromise" that would ensure access for French fishermen to UK waters.
The insistence of France and other northern fishing nations on maintaining access to British waters has been a key stumbling block in the talks so far.
"We know that we will have to make an effort. This effort must be reasonable," Barnier said.
The European leaders have tried to keep Brexit off the agenda at their recent summits but, in a sign that the topic was heating up, were ordered to leave their phones out of the room during the discussion.
The official statement offers little to Johnson and even dropped the line in an earlier draft that called for Barnier to "intensify" his discussions with Frost.
During the call to Johnson on the eve of the crunch talks, EU chief Ursula von der Leyen warned that there was "still a lot of work ahead of us", adding that Brussels wants a deal but "not at any price".
In a surprising twist, as the summit got under way she was forced to leave the venue and self-isolate after a member of her office tested positive for coronavirus.
Barnier said the talks could go on until the end of the October, the approximate date set by the EU side in order to leave enough parliamentary time to ratify the deal before the Brexit transition expires on December 31.
But London has accused Brussels of trying to force concessions by running down the clock.
- Rules of fair competition -
Britain left the European Union on January 31, but Barnier and Frost have been locked in months of inconclusive talks on a follow-on trade arrangement.
If no deal is reached, trade rules will revert to the bare bones of World Trade Organization regulations.
Both sides insist they are ready for this -- and would prefer it to having to accept a bad deal -- but experts forecast severe economic disruption.
Britain wants to reassert sovereignty over its waters and refuse EU legal oversight over the deal -- insisting it wants a simple trade deal of the kind the EU signed with Canada.
Brussels in turn stresses that Britain's economy is far more integrated with and closer to the EU's than Canada's, and that its single market must be protected from British backsliding.