Video report by ITV News Political Correspondent Romilly Weeks
Brussels has given Boris Johnson's new plan to resolve the Northern Ireland backstop conundrum a cool response.
While European Commission president Jean-Claude Juncker welcomed the proposals, he said there were "problematic points" particularly relating to the "governance of the backstop".
The prime minister's potential solution would see Northern Ireland effectively remain tied to EU single market rules for goods but leave the customs union.
Under his proposal, the arrangements would have to be approved by the currently suspended Assembly, which would then vote every four years on whether to keep them.
Mr Johnson wrote to Mr Juncker to say that it would be a “failure of statecraft for which we would all be responsible” if the two sides could not strike a deal before the October 17 European Council.
Michael Gove, the minister in charge of no-deal preparations, insisted there would be no physical checks at the Irish border.
He added: "If the EU reject these proposals out of hand then, in a way, they're saying they would prefer no deal to a new deal and no deal would certainly mean disruption to life and commerce to the island of Ireland, which is in no one's interests."
President Juncker spoke to Mr Johnson over the phone and confirmed to him that the Commission will now examine the legal text objectively.
The European Commission said meetings between the EU and UK negotiation teams will take place in Brussels over the coming days.
ITV News Political Correspondent Romilly Weeks explains how the PM's backstop plan would work
Its chief negotiator Michel Barnier and his team will update the European Parliament and the Council on Wednesday evening.
President Juncker will also speak to Taoiseach Leo Varadkar and "will listen carefully to his views", the Commission said.
Mr Barnier told reporters that while there had been progress, "to be frank, a lot of work still needs to be done to fulfil the three objectives of the backstop" - namely, no border, an all-Ireland economy, and protecting the single market.
"We will continue to work to reach a deal - the no deal will never be the choice of the EU. Never," he said.
"So we will continue to work with the UK team for a deal that respects and fulfils the three commitments of the backstop."
Mr Johnson had earlier acknowledged there was “very little time” but said “both sides now need to consider whether there is sufficient willingness to compromise and move beyond existing positions” to reach an agreement.
ITV News Europe Editor James Mates says Europe has been "careful not to be too negative" about the plan
Guy Verhofstadt, who chairs the European Parliament's Brexit steering group, said they were "absolutely not positive" about Mr Johnson's plan.
"It doesn't provide the necessary safeguards for Ireland," he said.
The view appeared to be echoed by Taoiseach Leo Varadkar who said the proposals did not fully meet the agreed objectives of the backstop.
Mr Varadkar and Mr Johnson discussed the proposed plans in a phone call on Wednesday evening.
Afterwards, a statement from the Irish Government said the Taoiseach would study the proposals further and consult with other EU leaders.
Jeremy Corbyn said the PM's proposal is "worse than Theresa May's deal" and added he "can't see it getting support".
Despite the prime minister urging compromise, Labour leader Corbyn said "everything to do with his behaviour and his language over the past few weeks has been about getting a no-deal Brexit".
And Leader of the Brexit Party Nigel Farage criticised Mr Johnson's Brexit proposals, saying the deal would be "like putting your head in a crocodile's mouth and hoping for the best."
He tweeted: "Boris only wants to change one part of the Withdrawal Agreement. Despite his words there is no guarantee that we will leave the customs union, and any future trade deal needs good faith from the EU side."
The DUP - the party Mr Johnson relies on to prop up his government in the Commons - is on board with the prime minister's plan.
It said further work was needed but urged all parties to approach discussions with a "positive mindset within a spirit" of wanting a new deal.
If talks with Mr Juncker breakdown, then, as ITV News Political Editor Robert Peston understands, Mr Johnson "won't bother going to the EU summit on October 17".
The Liberal Democrats Brexit spokesperson Tom Brake said the offer is "nothing short of derisory".
He wrote on Twitter: "Based on principles long deemed unworkable by NI and ROI businesses, and delivering nothing more than confusion at vast cost, either he has learned nothing, or he wants them to be rejected."
And the SNP, which wants the UK to remain in the EU, said it is now determined to "bring this dangerous government down."
Its Westminster leader Ian Blackford claimed the proposals had been offered so that the government would be "seen to be doing something".
He said: "At the end of the day what I expect Boris Johnson to try to do is to get us to leave the European Union on a no deal basis at the end of October, despite the fact there's an act of Parliament that actively forbids that."
An SNP source said: "The Lib Dems are acting as a roadblock and no credible alternative has been presented.
"What started as a constructive process that achieved results is going nowhere."
DUP leader Arlene Forster says her party is behind the PM:
In his letter, Mr Johnson said the backstop – the contingency plan agreed by the EU and Theresa May to prevent a hard border between Northern Ireland and Ireland – must be removed.
Unlike Mrs May’s plans for a UK-EU relationship with a closely integrated customs arrangement, Mr Johnson favoured a looser free trade deal and “in these circumstances the proposed ‘backstop’ is a bridge to nowhere”.
Mr Johnson said the plan had five elements:
A commitment to a solution compatible with the Good Friday Agreement
Confirmation of support for long-standing areas of UK-Ireland collaboration including the Common Travel Area and north-south co-operation
The potential creation of an all-Ireland regulatory zone covering all goods including agri-food
The consent of those affected by that all-Ireland zone with the Northern Ireland Executive and Assembly given the chance to endorse the plan before it comes into effect and then every four years
Northern Ireland will be fully part of the UK customs territory and outside the EU’s customs union.
Mr Johnson claimed the plan was “entirely compatible with maintaining an open border in Northern Ireland”.
He told Mr Juncker that because the goods trade between Northern Ireland and Ireland made up "a little over 1% of UK-EU total trade in goods" it was "entirely reasonable to manage this border in a different way.
Any risks arising from the proposals would be "manageable", particularly as imports from third countries would be controlled by EU and UK customs authorities.
Under the plan there would be "decentralised" customs regimes, with paperwork conducted electronically as goods move between the two countries.
But Mr Johnson acknowledged there would need to be a "very small number of physical checks", which he claimed could be conducted at traders' premises or other points in the supply chain - rather than at the border.
He called for the two sides to work together to find "flexible and creative solutions", coupled with a joint commitment "never to conduct checks at the border in future".
ITV News Political Correspondent Carl Dinnen reports from the border area in Ireland
Countdown to Brexit
October 17-18: EU council meeting where Mr Johnson will outline his plans to leaders of the 27 European states.
October 19: If there is no deal agreed at the council, then the PM must ask for a delay, if he abides by the Benn Act - or "Surrender Act" as Mr Johnson describes it.
October 31: If there's no deal and no delay, then the UK leaves the European Union, come what may.