Johnson given two-week deadline to produce UK's backstop alternative or "it's over," warns EU leader

In Paris, Mr Rinne expressed his and Mr Macron’s concern “about what is happening in Britain”.

He told reporters: “We need to know what the UK is proposing. Loose talk about proposals for negotiations is irresponsible…The UK should make its possible own proposals very soon if they would like them to be discussed.”

The Finnish premier then said: “We both agreed that it is now time for Boris Johnson to produce his own proposals in writing; if they exist. If no proposals are received by the end of September, then it’s over.”

Mr Rinne’s challenge came after UK Government sources suggested Britain was holding back its “Brexit blueprint” until after the Conservative Party conference in early October to pile the pressure on Brussels to secure a new deal before the crunch Euro summit on October 17.

Earlier, Jean-Claude Juncker, the outgoing President of the European Commission, complained that no real progress could be made until the UK submitted its formal written proposals.

Updating MEPs in Strasbourg, he warned them there remained a "palpable" risk of a no-deal Brexit despite "friendly, constructive and in part positive" talks with Boris Johnson earlier this week.

"I said to Prime Minister Johnson that I have no emotional attachment to the safety net, to the backstop, but I stated that I stand by the objectives that it is designed to achieve.

"That is why I called on the Prime Minister to come forward with operational proposals, in writing, for practical steps which would allow us to achieve those objectives.

"Until such time as those proposals have been presented I will not be able to tell you, looking you straight in the eye, that any real progress has been achieved," declared the EU’s top official.

But a No 10 source said: “We showed them the text of the Northern Ireland protocol without the backstop in it to show them the precision of the removal that we’re looking for, so they could understand what would still be left.”

He added: “Once you share it with 27 countries, you’re not in control of the document. You’ve got to be sensible about it.”

Michel Barnier, the EU’s chief negotiator, said the bloc still needed to hear more from the UK side about its proposals for replacing the backstop.

He noted: "The new UK Government this week in Luxembourg outlined the aspects of the backstop they don't like. That is not enough, however, to move towards achieving a solution."

The UK’s Brexit blueprint appears to fall into three categories; firstly, an “all-Ireland” market for food and agriculture; secondly, customs and regulatory checks on other goods undertaken away from the Irish border; and, thirdly, a key role for the Stormont Assembly overseeing the new arrangements, once it is back up and running; hopefully, during the transition period.

Last night, the Prime Minister and Mr Juncker had further talks on the phone with a No 10 spokesman saying: “They discussed the positive and constructive conversation they had in Luxembourg on Monday and their shared determination to reach a deal.”

In further phonecalls, Mr Johnson also discussed matters EU with David Sassoli, the European Parliament President, Nicos Anastasiades, the Cypriot President, and Arturs Karins, the Latvian Prime Minister.

“The Prime Minister updated the other European leaders on the progress of the Brexit talks to date and reiterated that, when the UK leaves the EU on October 31, his preference is that we do so with a deal. He spoke about the work that was underway to find an alternative to the backstop that protects both the Good Friday/Belfast Agreement and the integrity of the single market.”

Xavier Bettel, the Luxembourg premier, who humiliated the PM earlier this week by mocking him for abandoning a joint press conference because of noisy anti-Brexit protesters, denied it had been a planted ambush, saying he had too much respect for Britain and Mr Johnson to even contemplate such a move.

Meanwhile, Michelle O’Neill, Sinn Fein's deputy leader, made clear her party’s opposition to a “Stormont veto” on the Irish backstop because, she argued, a “backstop that can be vetoed is not a backstop".

Her remarks came after reports that Northern Ireland’s Democratic Unionists might consider endorsing the UK Government’s contingency plan aimed at preventing a hard border if the devolved institutions would have a veto on future EU rules applying to the province.

Speaking ahead of a speech at the Dublin Chamber of Commerce, Arlene Foster, the DUP leader, stressed how her party wanted a deal that worked for the UK constitutional position.

"I've heard from Europe today...about the majority in Northern Ireland wanting to have the backstop. But if you look at the Belfast Agreement, it's about parallel consent; it's about the consent of Nationalism and the consent of Unionism.

"There are no Unionist MLAs who support the backstop at present, so therefore there is a need to find a way forward which everybody can buy in to."

The DUP leader denied her party was softening its position on Brexit, stressing how it wanted a “sensible deal and a sensible way forward”.

She added: "There is a lot of commentary about the DUP being no-deal Brexiteers but as people look at the evidence they will find something very different."