Theresa May has admitted for the first time that Brexit negotiations have hit “difficulty” as she beseeched European leaders to give her a deal she can sell to the British people.

The Prime Minister explicitly conceded last night that talks were in trouble ahead of her key intervention in Florence two weeks ago, prompting her to try and get negotiations back on track.

She told Angela Merkel, Emmanuel Macron and other EU leaders that there is now the “urgent” need for progress with the threat of the UK crashing out of the EU without a deal looming.

Speaking on Thursday evening at a working dinner with other heads of government in Brussels, Ms May said that at the end of the summer she “recognised the difficulty the process was in”.

“I took stock, listened to what the people in the UK were saying, and what my friends and partners in Europe were saying, and I made a step forward,” she said.

The Prime Minister, who is attending a meeting of the European Council, told leaders that the Florence speech was designed to break the deadlock she had identified and called for a new “joint effort and endeavour”.

“There is increasingly a sense that we must work together to get to an outcome we can stand behind and defend to our people,” she said, adding that when the 27 remaining member states convene tomorrow to discuss Brexit in private “the clear and urgent imperative must be that the dynamic you create enables us to move forward together”.

The PM and world leaders dined on gnocchi and pheasant supreme at the dinner, followed by fresh pineapple.

Ministers fear collapse of Brexit talks 'within weeks' despite Theresa May's best efforts to kick-start process

European Commission chief negotiator Michel Barnier has repeatedly said he is “worried” about “deadlock” in negotiations, but the line from the UK government has always been significantly more optimistic, stressing “concrete progress”.

The PM’s intervention comes as the European Council appears set to refuse to allow the UK to move to trade and future relationship talks – which it has said can only start once “sufficient progress” has been made on settling the divorce bill, Northern Ireland border, and EU citizens’ rights.

The 27 remaining EU leaders will meet tomorrow to discuss Brexit without Ms May, whose address to dinner was not followed by any discussion or debate.

They are expected to tell Britain to come back in December once more progress has been made for another assessment of whether it is ready for trade talks.

Senior UK government officials also admitted that the prime minister was “working against a difficult political backdrop” at home – an apparent reference to Tory MPs who were pushing her for a no deal.

Arriving at the summit on Thursday Angela Merkel said she believed there were “encouraging” signs that sufficient progress could be made in December. Ms May said the summit was a time to take stock of the progress that had been made in talks so far.

Dutch prime minister Mark Rutte however told reporters in Brussels that Ms May had to “come up with more clarity on what she means by ‘other commitments’ in her Florence speech”.

Brexit: the deciders Show all 8 1 /8 Brexit: the deciders Brexit: the deciders European Union's chief Brexit negotiator, Michel Barnier Getty Brexit: the deciders French President Emmanuel Macron Getty Brexit: the deciders German Chancellor Angela Merkel Reuters Brexit: the deciders Commission President Jean-Claude Juncker EPA Brexit: the deciders The European Parliament's chief Brexit negotiator Guy Verhofstadt Getty Brexit: the deciders Britain's Prime Minister Theresa May Getty Images Brexit: the deciders Britain's Chancellor of the Exchequer, Philip Hammond PA Brexit: the deciders After the first and second appointed Brexit secretaries resigned (David Davis and Dominic Raab respectively), Stephen Barclay is currently heading up the position PA

“I phoned her last week, and tried to encourage her to do that and so far she hasn‘t,” he said.

The Prime Minister’s spokesperson told journalists in Brussels: “The Florence speech intended to create momentum and we achieved that. In all our talks with EU leaders they have been responsive and we hope that will continue.”