BRUSSELS: European Council President Donald Tusk said on Tuesday he will ask British Prime Minister Theresa May this week if she has new ideas on how to break the impasse in Brexit talks, adding that he has become less optimistic about an immediate breakthrough.

Tusk told reporters his hopes for their meeting on Wednesday had been dampened by European Union Brexit negotiator Michel Barnier, as well as events in the British parliament.

“Unfortunately the report on the state of the negotiations that I got from Michel Barnier today, as well as yesterday’s debate in the House of Commons, give me no grounds for optimism before tomorrow’s European Council on Brexit,” said Tusk, who will chair the EU summit in Brussels.

A breakthrough required more than just goodwill. “Tomorrow, I’m going to ask Prime Minister May whether she has concrete proposals on how to break the impasse. Only such proposals can determine if a breakthrough is possible,” he said.

EU leaders, meeting from Wednesday evening, had hoped to reach a provisional deal over Britain’s exit from the EU in March before signing off on a withdrawal agreement at a special Brexit summit in November.

Tusk said the November meeting would make sense only if there were a feeling of being really close to a breakthrough.

The talks are stuck over the issue of the border between the British province of Northern Ireland and the Irish Republic, and have not resumed since Sunday.

Tusk likened the issue to the Gordian Knot, cut in legend by Alexander the Great, saying “It is not so easy to find this kind of creative leader.” Leaders, he said, would step up their preparations for a no-deal Brexit. “A no-deal scenario becomes more likely than ever before, but it doesn’t mean it is our political priority.”

The EU’s chief Brexit negotiator Michel Barnier on Tuesday called for more time to reach a deal with London, as fears grow about Britain crashing out of the union with no agreement in place.

Barnier said there were still several important differences between the two sides, notably on the thorny question of the Irish border.

As he arrived to brief EU ministers meeting in Luxembourg on the state of negotiations on the eve of a crucial summit, Barnier said “we’re not there yet”.

“We need more time to find a comprehensive agreement and achieve the decisive progress that is needed to finalise this negotiation on the UK’s orderly withdrawal,” he told reporters.

“We are going to take this time calmly, seriously to reach this comprehensive agreement in the coming weeks.”

The latest round of talks between Barnier and his British counterpart Dominic Raab ended without breakthrough on Sunday, casting doubt on the chances of reaching a deal this week.

British Prime Minister Theresa May will pitch to EU leaders in Brussels on Wednesday at a summit which had been billed as the last chance to agree a draft deal in time for Brexit day on March 29.

One of the main sticking points is what to do about the land border between EU member Ireland and British-ruled Northern Ireland.

London and Brussels say they want no checks imposed at the border, but the problem persists of how to square that aim with Britain’s decision to leave the EU’s single market and the customs union.