The French government has warned it could veto a Brexit trade deal that includes too many compromises, amid reports that an agreement could be "imminent".
A deal is now expected before the end of the weekend, barring any last-minute break down in talks, according to an EU official close to negotiations who spoke to the Reuters news agency.
But a less positive tone is coming from Downing Street, which warned on Friday that talks were at a “very difficult point”.
Speaking on Friday morning French Europe minister Clement Beaune warned: "If there was an agreement and it was not good, we would oppose it with a right of veto."
He told French broadcaster Radio Europe 1: “We have to prepare for a risk of no deal but this is not what we want. I still hope that we can have an agreement but we will not accept a bad deal for France.”
The last 24 hours of negotiations have been a rollercoaster of conflicting reporters, with a senior UK government official last night accusing the European side of ruining the chances of an accord by introducing new elements.
The British official claimed that chance of an agreement were “receding” despite progress this week.
But there was renewed optimism on Friday morning after negotiators worked late into the night in their London bolt-hole, and Michel Barnier’s team confirmed he would stay in situ again going into the weekend.
Questions remain on the EU side about whether all EU member states could back the emerging deal, with Emmanuel Macron’s France leading a group of other more sceptical countries like the Netherlands and Belgium.
Mr Macron’s government has reportedly been pushing for the EU to hold out past the no-deal deadline on 31 December in a bid to extract further concessions from the British side, which would be hit most acutely by an uncontrolled exit from the single market and customs union.
But others like Ireland, which would also be hit hard by a no-deal, have said this is a risky strategy and that a free trade agreement is not guaranteed if left to 2021.
“For Britain and Ireland, the cost and the disruption that will flow from not being able to put a future relationship agreement in place in the next few days is very, very significant,” warned Irish foreign minister Simon Coveney on Thursday during a diplomatic visit to Paris to try and smooth over the differences, at what he described as “very sensitive moment” in Brexit talks.
Chief negotiator Michel Barnier’s planned update to EU ambassadors today has been cancelled, as he holds out for more concrete news to give to member states. A spokesperson for the EU council presidency said: "There will be no Coreper on EU-UK talks today due to the ongoing intensive negotiations in London. Keep your fingers crossed and stay tuned."
Speaking on Friday morning at a virtual press conference from Brussels, European Council president Charles Michel sent the ball back to the British court, telling reporters: “The real question is, which political, economic, social project do they want for their own future? And this is a question for the British government and for the British people.”
Mr Michel, a former Belgian prime minister whose job is to speak for member state governments collectively, added: “If one side of the table rejects [a tentative agreement], it’s a no-deal. We will need to assess what will be probably on the table.”
Boris Johnson and European Commission president Ursula von der Leyen are widely expected to speak by telephone this weekend, though no call has yet been added to either leader’s diaries.
A Downing Street spokesman told reporters in Westminster on Friday that talks had ended at 11pm on Thursday evening and were continuing today.
Whether negotiations would carry on through the weekend would be “contingent on the progress of talks today”, he said.
The spokesman said: “There are still some issues to overcome. Time is in very short supply and we are at a very difficult point in the talks.
“What is certain is that we will not be able to agree a deal which doesn’t respect our fundamental principles on sovereignty and taking back control.
“The prime minister has been clear we will continue to work hard to reach an agreement on the basis we have set out. An agreement on any other basis is not possible.”
Mr Johnson will be working at Chequers over the weekend and will be kept up to date on progress in talks, said the spokesman.
After the passing of an informal deadline in mid-November, the weekend is increasingly being seen as the new end point for talks. Monday will see the British government press ahead with new legislation to override the Brexit withdrawal agreement, a move which the EU says would be “curtains” for negotiations.
The key stumbling blocks remaining are the question of state aid and fair competition between companies, how disputes will be dealt with, and the extent to which EU fleets will retain rights to fish in British waters.
If no agreement it put in place by 31 October the UK and EU will revert to trading on World Trade Organisation terms. Significant disruption is expected even if an agreement is signed, but the economic impact from a no-deal would be the most acute, and entail price rises for consumers thanks to new tariffs.