The EU instead want reworked plans submitted by the end of the week, with time running out ahead of the summit
Britain hinted Sunday that it could be open to changes to its latest Brexit proposals for Northern Ireland, as European leaders piled pressure on Prime Minister Boris Johnson to revise the plans.
Brexit Secretary Stephen Barclay reiterated that the ideas formally submitted to Brussels this week were "a broad landing zone" to be discussed during "intense negotiations in the coming days."
He urged the bloc to show "creativity and flexibility" to secure a deal ahead of October 31 - when Johnson has vowed Britain will end its 46 years of EU membership with or without an agreement.
"We've set out very serious proposals including compromise on our side," Barclay told the BBC.
"We do need to get into the intensive negotiations on the text to clarify what the deal is."
Barclay added the government was considering holding a parliamentary vote ahead of a make-or-break EU summit on October 17-18 to show bloc leaders that Johnson's plans have MPs' support.
But European leaders, who have reacted tepidly to the propositions and urged London to offer a revised, viable way forward, are yet to agree even to ramp up negotiations.
Brussels reportedly balked at Britain's request to keep initial discussions on the proposals going through the weekend, and they will resume Monday.
The EU instead want reworked plans submitted by the end of the week, with time running out ahead of the summit.
"If the offer from the UK turns out to be a take-it-or-leave-it, it's going to be very difficult," Latvian Prime Minister Krisjanis Karins told the BBC on Sunday.
"It's fully dependent on the will of Mr Johnson because from the European side, we're always open and looking towards a deal."
'No more dither'
Johnson began phoning European leaders this weekend to sell his proposals, but has so far received scant encouragement for a deal based around them.
Dutch Premier Mark Rutte tweeted he had told Johnson "important questions remain about the British proposals" and "there is a lot of work to be done ahead" of the summit.
Meanwhile the EU's top negotiator Michel Barnier told an event Saturday organised by French newspaper Le Monde that while an agreement was still possible it "will be very difficult to reach".
The British leader is hoping the threat of a messy no-deal departure in less than three weeks could force the EU to compromise.
That comes despite British MPs passing a law last month that requires him to seek another Brexit delay if he fails to secure an agreement by the end of the summit.
Barclay reiterated Sunday that the government would comply with the legislation.
But in identical articles for two Brexit-backing British tabloids, Johnson insisted the country will leave the bloc later this month.
"They should be under no illusions or misapprehensions," he wrote in the Sunday Express.
"There will be no more dither or delay. On October 31 we are going to get Brexit done."
'Ready to work'
The British proposals submitted to Brussels Wednesday centre on how to manage the post-Brexit border between British province Northern Ireland and EU member 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 Britain, with required checks to rely on untried technology and carried out away from the sensitive border.
Brussels has said the plans "do not provide a basis for concluding an agreement."
It sees the potential for rampant smuggling while Ireland is concerned hardline Northern Irish unionists would have an effective veto.
Barclay, who will travel to Amsterdam later Sunday for Brexit talks, hinted that Britain could be willing to consider alternative ways of meeting its aims.
"We're ready to work on that," he said.
Ireland's leader Leo Varadkar said Saturday there is "plenty of time" to put forward alternatives and he was trying to arrange a meeting with Johnson next week, Irish broadcaster RTE reported.