Theresa May told her cabinet on Tuesday morning that there was still a "small number of outstanding issues" to be resolved for the UK and Brussels to finalise a Brexit agreement.
At the weekly cabinet meeting, the British prime minister said there was still some way to go before a “best text” could be agreed, officials said.
Asked when the talks with the EU might conclude, a Number 10 spokesman replied: “How long is a piece of string?”
Speaking in a BBC interview ahead of the meeting, David Lidington, the de facto deputy prime minister, said he was "optimistic because we have managed to get things down to a small number of difficult issues outstanding".
Mr Lidington was also non committal about whether a deal might be struck in the next 24 to 48 hours. “[It’s] still possible but not at all definite.”
Mrs May still hopes that the EU will convene a special European Council meeting on November 25th to sign off an agreement, leaving her very little time to agree an exit text.
UK officials have admitted that unless there is a breakthrough by the end of Wednesday, the timetable for an EU Brexit summit could slip into December.
Mrs May wants to win parliamentary approval for any deal before Christmas.
Dominic Raab, Brexit secretary, has told colleagues the government will start implementing contingency plans for a no-deal outcome, if no progress has been made.
Cabinet ministers discussed Brexit for 45 minutes during the meeting at Downing Street that also covered NHS preparedness for a winter crisis and an update on military veterans.
Mr Raab led a discussion of government preparedness on a no-deal Brexit and Mrs May briefed cabinet ministers on the progress of the negotiations.
Backstop
The biggest obstacle remains the exit mechanism that would allow Britain to leave a temporary customs arrangement – a backstop to avoid the reintroduction of a hard border in Ireland.
Eurosceptic ministers, who met in trade secretary Liam Fox’s office on Monday to co-ordinate tactics, insist Britain must have the right to walk away from the arrangement.
The EU is insisting on a joint review mechanism to end the temporary arrangement, which would last until a permanent UK/EU trade deal put in place a frictionless border in Ireland.
Eurosceptic ministers will resist any role for the European Court of Justice in this mechanism.
A number of pro-Brexit ministers have warned privately that a no-deal outcome would be better than any deal that could theoretically leave Britain trapped in a customs union.
Given the proximity of the two sides to a deal, it is likely that Mr Raab and Mr Barnier will be involved in the final stage of negotiations to give a political impetus to the talks. – Copyright The Financial Times Limited 2018