The latest talks aimed at breaking the Brexit deadlock over the Northern Ireland backstop have failed to achieve a breakthrough, the European Commission has said.
The commission said there was still "no solution" to the impasse after the meeting yesterday in Brussels between the European Union's chief negotiator Michel Barnier and Attorney General Geoffrey Cox and Brexit Secretary Stephen Barclay, with barely over three weeks to go before Britain's scheduled exit on 29 March.
Talks by lower-ranking officials were expected to continue today, but there was no clear schedule yet for further negotiations between Mr Cox and Mr Barnier.
Mr Barnier told the weekly meeting of the College of Commissioners in Brussels that the negotiations were proving "difficult" and a way forward had not been found.
The commission's chief spokesman Margaritis Schinas told reporters: "Michel Barnier was present and informed the commissioners that while the talks take place in a constructive atmosphere, discussions have been difficult.
"No solution has been identified at this point that is consistent with the Withdrawal Agreement, including the protocol on Ireland/Northern Ireland which, as you all know, will not be reopened."
At the heart of the deadlock is the Irish "backstop", an insurance policy the EU wants to ensure no return to a hard border.
Mr Cox said that yesterday’s discussions in Brussels were "robust" and detailed, and would be resuming soon.
Diplomats speculated that, if EU and UK negotiators could seal a deal over the weekend, Mrs May could come to Brussels on Monday to give it political endorsement and take it back to London just a day before the House of Commons votes on it.
"It's unlikely there would be a deal before the weekend," an EU official said.
"We are preparing for a working weekend."
The EU's 28 leaders including Mrs May will decide at a 21-22 March summit whether to extend the Article 50 negotiating period beyond 29 March.
"How long an extension will depend on the House of Commons vote," the diplomat added.
The EU will be watching the British parliament's action next week but few in Brussels believed the deal would be ratified by deeply split UK MPs in their second go at it, which comes two months after they resoundingly rejected the package.
With 23 days left until Brexit and fears that an abrupt divorce without a pre-negotiated settlement could spell economic turmoil, the EU is now nudging London to delay its departure.
Mrs May last week opened the way to a short extension of the Article 50 period and the EU sees a delay until the end of June as relatively easy.
But EU leaders have also mooted a longer delay, even though that would risk interfering with European Parliament elections due in May.