Theresa May has delayed a fresh Commons showdown over her Brexit deal until the new year as she acknowledged it will take time to win the assurances she is seeking from EU leaders.

After the UK Prime Minister survived a bruising no confidence vote by her party’s MPs on Wednesday, Downing Street said the “meaningful vote” on the Withdrawal Agreement would not now be brought to Parliament before Christmas.

Arriving in Brussels for an EU summit, Ms May acknowledged she needed fresh assurances from EU leaders regarding the operation of the Northern Ireland backstop if the agreement was to get through the House of Commons.

However, she played down the prospect of an “immediate breakthrough” during the two-day gathering in the Belgian capital.

Austrian Chancellor Sebastian Kurz, who currently holds the rotating EU presidency, suggested there could be a special Brexit summit in January to agree “additional assurances” which could be attached to the Political Declaration on the UK’s future relationship with the EU.

A Downing Street spokeswoman confirmed that it was the Government’s aim to hold the vote in the Commons “as soon as possible in January”.

The vote had been due to take place on Tuesday, but was dramatically pulled after the whips warned the Prime Minister she was heading for a heavy defeat unless she delayed.

The move was met with anger on all sides, prompting a further flurry of letters from Conservative MPs which triggered Wednesday’s no confidence vote.

While Ms May said she was “grateful” to those MPs who backed her, with more than a third of the parliamentary party calling for her to go, she accepted their concerns had to be addressed.

“My focus now is on ensuring that I can get those assurances that we need to get this deal over the line, because I genuinely believe it’s in the best interests of both sides – the UK and the EU,” she said.

In a last minute change to the summit arrangements, the Prime Minister was addressing the EU leaders and taking their questions on Brexit at the end of opening session on Thursday.

She will then leave while the remaining 27 discuss their response over dinner.

EU leaders indicated their willingness to help Ms May through “clarifications” to the Brexit deal, but were adamant they would not re-open negotiations on the Withdrawal Agreement.

French President Emmanuel Macron said: “We cannot reopen a legal agreement, we can’t renegotiate something which has been negotiated over several months. We can have a political discussion in this context.”

Irish premier Leo Varadkar, who held a lengthy one-to-one meeting with Ms May ahead of the main summit, said she had to honour her commitments on the backstop, intended to ensure there is no hard border between Northern Ireland and the Republic.

In particular, he insisted there could be no “unilateral exit clause” as some MPs are demanding amid concerns that the UK could be tied to EU customs arrangements if the backstop is activated.

“If the backstop has an expiry date, if there is a unilateral exit clause, then it is not a backstop. That would be to render it inoperable,” he said.

Reports from Brussels on Thursday suggested EU leaders were considering a draft document stating the bloc “stands ready to examine whether any further assurance can be provided” to the UK on the backstop.

It said that if the backstop was ever activated, the EU would seek to ensure it “would only be in place for a short period and only as long as strictly necessary”.

But such assurances are unlikely to satisfy hardline Brexiteers who have been demanding the backstop is dropped altogether.