Theresa May has said she could ask MPs to vote for her Brexit deal before the EU has agreed to it.

Asked whether Brussels would need to formally approve any agreement before the Commons voted on it, the prime minister said on Monday: “It is possible to do it either way.”

May has said the so-called meaningful vote on any proposed deal will take place by March 12.

It came as Donald Tusk said delaying Brexit by extending the Article 50 process was now a “rational solution” given the how close the UK is to exit day on March 29.

Speaking at a press conference following a summit in Sharm el Sheikh, May said she still wanted to UK to leave the EU on March 29.

“Any delay is a delay,” she said. “An extension to Article 50, a delay in this process, doesn’t deliver a decision in parliament, it doesn’t deliver a deal.”

The prime minister now faces the prospect of another potentially damaging Commons revolt on Wednesday when MPs are expected to mount a fresh attempt to block a no-deal break and extend Article 50.

In recent days three pro-EU Cabinet ministers – Amber Rudd, David Gauke and Greg Clark – signalled they could be prepared to vote for it if there was no breakthrough in the negotiations.

There was speculation that up to 100 Tory MPs – including as many as 20 ministers – could be prepared to join them as patience among MPs opposed to no deal is stretched to breaking point.

Labour MP Yvette Cooper, who drew up the amendment with Conservative former minister Sir Oliver Letwin, said it would now become the “real meaningful vote” on the Brexit deal.

In order to extend Article 50, the EU would have to agree. It was reported over the weekend that Brussels would prefer a 21-month extension rather than a short two-month delay.

Eurosceptic Tory MPs are deeply opposed to extending Article 50, with many believing it to be part of a plot by pro-Remain campaigners to stop Brexit all together.