Britain’s main opposition Labour Party has announced that it will push for a second Brexit referendum if its demands are not met in parliament.

“If parliament rejects our plan, then Labour will deliver on the promise we made at our annual conference and support a public vote,” Labour’s Brexit spokesman Keir Starmer announced on Twitter on Monday.

The Labour Party has said it will be putting forward an amendment calling on the government to adopt its Brexit proposals, which push for close alignment with the European Union’s single market and specifically seek a permanent customs union with the bloc.

Labour also seeks to force UK Prime Minister Theresa May to delay Brexit beyond the scheduled exit date of March 29 by extending the Article 50 negotiating period.

Labour leader Jeremy Corbyn’s office announced on Monday that the opposition leader was due to tell a meeting of his lawmakers that the party “will do everything in our power to prevent no deal”.

“We are committed to also putting forward or supporting an amendment in favor of a public vote to prevent a damaging Tory (Conservative) Brexit being forced on the country,” Corbyn was due to announce in the meeting.

Lawmakers in the House of Commons rejected May’s deal with the EU on January 15 and forced her to gain concessions from Brussels that could make the agreement acceptable to the chamber.

However, the EU has hardly budged on its position, insisting that a controversial mechanism to ensure there would be no border on the island of Ireland after Brexit would not change.

Earlier in the day, European Council President Donald Tusk suggested that delaying Brexit would be a “rational solution”, claiming that there is no majority in the British parliament to approve a divorce deal.

Speaking at a press conference on Monday, May, nonetheless, stressed that Britain will under no circumstances delay the planned departure,

“An extension to article 50, a delay in this process, doesn’t deliver a decision in parliament, it doesn’t deliver a deal,” May said, adding that “it’s within our grasp to leave with a deal on 29 March and that’s where all of my energies are going to be focused.”

On Sunday, May announced that the final parliament vote on the deal will be delayed until March 12, only little more than two weeks before the Brexit deadline.