Brexit talks with Brussels could continue over the weekend as Boris Johnson continues efforts to sell his plans to the European Union.
European leaders have given his proposals short shrift in public, with senior figures dubbing his “two borders” plan for Northern Ireland “unconvincing”.
Brussels said that “every day counts” as the clock ticks down to a crunch summit of EU leaders on October 17-18 and Downing Street said “we are ready to talk at any point”.
The Prime Minister is expected to embark on a tour of European capitals for face-to-face talks next week as well as continuing to speak by phone to counterparts.
Although the European Commission said there was no formal deadline for talks to make progress, officials made clear that time was tight.
Commission spokeswoman Natasha Bertaud said: “What we have always said is that every day counts, especially as we near the end of October.
“Technical-level meetings are currently ongoing in order to give the United Kingdom opportunity to present their proposals in more detail but no deadline has been set.”
The Prime Minister’s Europe adviser David Frost is having further technical talks with officials in Brussels, and Downing Street said the UK was prepared to continue discussions over the weekend.
A Number 10 spokeswoman said: “I think it’s clear that all sides want a deal.
“What we have done is put forward fair and reasonable proposals to help us negotiate a new deal.
“The Commission, who obviously we will be negotiating with, welcomed our determination to advance talks and make progress towards that deal.”
The spokeswoman added: “We are ready to talk at any point, including over the weekend.”
She also indicated the Government would consider publishing the full legal text, which has so far only been shared confidentially with Brussels.
Meanwhile, Mr Johnson faces another showdown with the courts as his opponents look to force him to comply with measures which could require a delay to Brexit,
The legal action – led by businessman Vince Dale, SNP MP Joanna Cherry QC and Jolyon Maugham QC – will ask the Court of Session in Edinburgh to require Mr Johnson to seek an extension to avoid leaving the EU without a deal.
It could also later see a court official being given the power to sign the letter if the Prime Minister refuses to do so.
The Court of Session’s Inner House heard the unique power of nobile officium – which would allow a court official to sign the letter requesting an extension – has never been used over a Prime Minister.
Mr Johnson has repeatedly said he is prepared to take the UK out without a deal on October 31 – despite the Benn Act committing him to requesting an extension to Article 50 if a deal is not secured following the European Council summit.
The PM told MPs in the Commons on Thursday that he had made a “genuine attempt to bridge the chasm” with Brussels by making compromises as time runs out before the Halloween Brexit date.
The plans met with resistance in Brussels and Dublin.
Irish premier Leo Varadkar said the Brexit plan “falls short in a number of aspects” while his deputy Simon Coveney said “if that is the final proposal, there will be no deal”.
And Donald Tusk, president of the European Council – the body made of up national leaders – said he told Mr Johnson “we remain open but still unconvinced” during talks on Thursday.
Downing Street said the proposals to address problems with the Irish border were the “broad landing zone” and the “basis for discussion” in a conciliatory move after Number 10 sources had previously claimed they represented a final offer to Brussels.
Mr Johnson’s plans would see Northern Ireland apply EU rules on goods but stay in a customs territory with the UK.
This would create a regulatory barrier for goods crossing the Irish Sea and create a customs border between Northern Ireland and the Republic of Ireland – but Mr Johnson has insisted there would be no need for checks or infrastructure at the frontier.
Mr Coveney said: “We don’t see how the proposal to have two different customs territories on the island of Ireland can avoid customs checks between those territories, we don’t see how that works and the EU has the same concern, so that element of the proposal needs to be developed further.”
The plans require the currently suspended Northern Ireland Assembly to approve the new arrangements, with a subsequent vote every four years – something which has caused concern in Ireland.
Northern Ireland Secretary Julian Smith suggested that reform of the contentious Stormont voting system could be “helpful” in addressing concerns about handing the DUP a veto over the proposals.
The petition of concern voting mechanism could essentially hand one Northern Ireland party, potentially Mr Johnson’s DUP allies, the ability to block the plan, even if a majority of MLAs at Stormont support it.