PARIS (Reuters) - France is ready to veto any British request for a Brexit delay that either kicks the can down the road without offering a way out of its deadlock or imperils European Union institutions, an official in President Emmanuel Macron’s office said on Tuesday.

FILE PHOTO: Britain, European and French flags are seen before a news conference at the Elysee Palace in Paris, France, July 21, 2016. REUTERS/Philippe Wojazer

The warning came as Britain planned to ask the EU to extend the negotiating period by at least three months after Prime Minister Theresa May’s plans for another vote on her twice-defeated divorce deal were thrown into turmoil.

The Elysee official’s comments were the strongest indication yet from Macron’s office that France will not agree to an extension beyond the scheduled March 29 leave date simply to save Britain from a chaotic exit with no deal.

Asked about a possible French veto, the official said: “it is a possible scenario, yes, if the conditions for an extension are not met.” Any extension has to be approved by all 27 EU members remaining in the bloc.

Macron, an ardent Europhile, has championed an EU refusal to reopen at the eleventh hour Britain’s withdrawal agreement, the result of more than two years of hard-fought negotiations.

The presidential aide said France would assess any request for an extension against two criteria: is there a credible British plan, or strategy, that can win a majority in Westminster; and what will the impact be on the smooth running of Europe’s institutions?

An extension beyond late June, a month after European elections in late May, could see Britain maintain a commissioner in the EU executive, lawmakers in the European Parliament and a seat at the table of EU leaders, with influence on decisions for the bloc’s future even as it tries to leave.

A no-deal exit by Britain was “not desirable, was not being pushed by the EU, by France or other member states, but will impose itself on us if no real alternative is put forward in the next few days or even the next few hours,” the official added.

May’s spokesman said on Tuesday the prime minister was writing to European Council President Donald Tusk to ask for a delay. He did not disclose how long a delay she would seek, but said she believed it should be as short as possible.

May had earlier told parliament that if it did not ratify her deal, she would ask to delay Brexit beyond June 30, a step that Brexit advocates fear would endanger the entire divorce.

French officials say in private that they are not alone in their stance but that they are more willing than other countries to stick their necks out because Britain will always blame the French for their misfortunes.

In Brussels, Germany’s Europe Minister Michael Roth complained that EU patience was being sorely tested by London but adopted a softer tone than Paris, saying Germany’s main aim was to avoid a no-deal Brexit, which would disrupt business across the continent.

“Everything has been done to avoid a no-deal and a disorderly British exit,” the French presidency official said. “Now, we need a clear political choice in the United Kingdom.”