Donald Tusk handed Boris Johnson a last-minute reprieve after talks with Leo Varadkar raised the prospects of a Brexit deal, but he warned the UK still has not presented a “workable, realistic proposal”.

The European Council president also welcomed “promising signals” reported by the Irish Taoiseach, speaking as Brexit Secretary Stephen Barclay and EU chief negotiator Michel Barnier held what was described as a “constructive meeting”.

The tepid positivity came after Mr Johnson and Mr Varadkar said they could “see a pathway” to a possible agreement following face-to-face discussions in the Wirral.

Negotiators were dispatched for talks in Brussels on Friday, with reports suggesting their success paved the way for an entry into the “tunnel” phase of intensive and secretive discussions.

Belgium EU Brexit
Mr Barclay and Mr Barnier meet in Brussels (Francisco Seco/AP)

As that meeting was under way, Mr Tusk revealed he had threatened the PM with publicly announcing on Friday that he had exhausted all opportunities of securing a deal by the crucial EU summit on October 17 and 18.

But he ruled out making that declaration, offering to hold out for the “slightest chance” of success, after speaking with the Taoiseach.

The PM had promised the EU to present a solution that would “satisfy the hardcore Brexiteers” while upholding the EU’s demands to have no hard border on the island of Ireland, protect the Good Friday Agreement and ensure the integrity of the single market, Mr Tusk said.

“Unfortunately we are still in a situation in which the UK has not come forward with a workable, realistic proposal,” he continued.

“A week ago I told Prime Minister Johnson that if there was no such proposal by today I would announce publicly that there are no more chances because of objective reasons for a deal during the coming European council.

“However, yesterday when the Irish Taoiseach and the UK Prime Minister met they both saw for the first time a pathway to a deal.

“I have received promising signals from the Taoiseach that a deal is still possible.

“Of course there is no guarantee of success and the time is practically up but even the slightest chance must be used.”

A short while later, Mr Barnier has hailed a “constructive meeting” with Mr Barclay, as leaders eyed a glimmer of hope for brokering a new divorce deal.

Mr Barnier compared the UK’s departure from the European Union to climbing a mountain, stressing the need for “determination and patience”.

On his way out, Mr Barnier told reporters they had held a “constructive meeting” and that he was going to meet with ambassadors of the EU27 and the European Parliament’s Brexit steering group before planning the next move.

A statement from the UK Government also described it as a “constructive meeting”.

The meeting between Mr Johnson and Mr Varadkar at a country manor on the Wirral on Thursday came after a week of abrupt exchanges between London, Dublin and Brussels.

Dramatic progress could lead to the start of so-called intensive “tunnel” negotiations in the coming days, ahead of the crunch EU heads of government summit.

The unexpectedly cordial atmosphere of the meeting between the two premiers led to speculation over a possible compromise on the contentious issue of the Northern Ireland border backstop.

Sterling rose sharply on international money markets in the wake of the talks, on which Cabinet received a briefing on Friday morning.

The Taoiseach said a deal was possible after more than two hours of talks but warned that “there’s many a slip between cup and lip”.

He refused to be drawn on any “concessions” made by either side, while UK Government sources would not comment on Irish press reports suggesting “significant movement” by the UK.

The softer mood music after Mr Johnson’s meeting with the Taoiseach followed an intensive few days which saw an acrimonious war of words explode and the talks appear close to collapse.

Briefings by anonymous Downing Street sources had accused Mr Varadkar of backtracking on previous commitments to try to find a deal, and of refusing to negotiate.

And following a heated telephone call between Mr Johnson and German Chancellor Angela Merkel on Tuesday, Number 10 sources claimed the EU was making it “essentially impossible” for Britain to leave with a deal.

Countdown to leaving the EU
(PA Graphics)

On Wednesday, Mr Barnier told the European Parliament there was still no basis for a fresh agreement.

He said the UK had yet to put forward an “operational, legally binding solution” to replace the Northern Ireland backstop – intended to prevent the return of a hard border with the Republic.

Without a deal, Mr Johnson will face demands from opposition parties to comply with the so-called Benn Act which would require him to request a three-month Brexit delay if there is no agreement by October 19.

The PM has said that, while he will abide by the law, he is determined to leave on the Halloween deadline of October 31 come what may.

Government sources have said ministers are preparing to hold an emergency Saturday sitting of Parliament on October 19.

Many MPs believe if he cannot get a deal, Mr Johnson will use the occasion to push for a “people versus Parliament” general election, possibly as early as next month.

If a deal did emerge, Mr Johnson would also need the backing of the DUP and Eurosceptic Tories to have any chance of getting it through without opposition support.