Johnson's Brexit envoy, senior diplomat David Frost, met EU officials in Brussels as the countdown to Friday deadline for striking a new deal in time for an EU summit next begins.
The EU restarted Brexit talks with Britain on Monday hoping to hear fresh ideas from Prime Minister Boris Johnson to answer grave European concerns about his new divorce deal proposal.
Johnson's Brexit envoy, senior diplomat David Frost, met EU officials in Brussels as the clock ticks down to Friday – the effective deadline for striking a new deal in time for an EU summit next week.
European leaders reacted sceptically to London's suggestions last week for replacing the Brexit deal reached with Johnson's predecessor Theresa May, which was rejected by British MPs three times, to avoid Britain crashing out in a chaotic "no deal" on October 31.
Serious doubts have been voiced about Johnson's new proposals for avoiding a hard border between EU member Ireland and British-ruled Northern Ireland, particularly the details on customs procedure and the role of the Northern Irish assembly.
In an interview with Le Monde newspaper at the weekend, chief EU negotiator Michel Barnier warned that if the British government "does not come back with new proposals on the two serious problems we have indicated to them, I cannot see how we can move forward".
Britain insists its offer represents significant concessions and now the EU must show similar flexibility, but Brussels is adamant it will not agree to any plan that undermines its single market or leaves Ireland exposed.
"This is the chance to get a deal done: a deal that is backed by parliamentarians and a deal which involves compromise on all sides," a UK source said.
"The UK has made a big, important offer but it's time for the commission to show a willingness to compromise too. If not the UK will leave with no deal."
Brexit minister Stephen Barclay on Sunday signalled London could be willing to soften its position on Northern Ireland, describing last week's suggestion as "a broad landing zone" rather than a final take-it-or-leave-it offer – as it had been described by British government sources earlier in the week.
During telephone talks with Johnson on Sunday, French President Emmanuel Macron made it clear that the EU would decide by the end of this week whether a deal is possible.
The British proposals submitted to Brussels last week centre on how to manage the post-Brexit border between Northern Ireland and Ireland.
Johnson wants Northern Ireland's devolved assembly – which has been suspended for almost three years – to vote every four years on whether to maintain EU rather than British regulations there.
He has also proposed the province leaves the EU's customs union along with the rest of the UK, with required checks to rely on untried technology and carried out away from the sensitive border.
Brussels has said these plans are not a basis for an agreement.