French president Emmanuel Macron has vowed to block an extension of Article 50 unless the UK had a "clear objective" based on a "new choice".
"We would support an extension request only if it was justified by a new choice of the British," Mr. Macron told reporters. "But we would in no way accept an extension without a clear objective."
He added: "As [EU Brexit chief] Michel Barnier said, we don't need time — we need decisions."
Spanish prime minister Pedro Sanchez warned that UK prime minister Theresa May would be "prolonging uncertainly" by postponing Brexit without a realistic plan. “Although Spain is not going to oppose the concession of an eventual extension, it must have a certain perspective of resolution,” the Spanish PM said.
He added: “Prolonging uncertainty by postponing deadlines is not a reasonable nor desirable alternative."
But Chancellor Merkel used softer language in her response, stating that the EU "won't say no" if the UK needed more time. "But we want an orderly withdrawal of the UK from the EU. We regret this decision but that’s the reality.”
France can veto an extension to Article 50 as all EU members must unanimously agree to the extension, with Mr. Macron's demand complicating matters for London. His statement also plays into the hands of Labour's bid to back a second referendum, which Labour backed on Wednesday.
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After meeting with Mrs. May, EU Council president Donald Tusk also said that delaying Brexit was a "rational" choice, but added that the British prime minister could still avoid an extension.
Ms. May proposed extending Article 50 to MPs on Tuesday in order in order to prevent another defeat in Commons. She faces another 'meaningful vote' on 12 March and if it is rejected, MPs will be requested on 13 March to vote whether the UK should leave the EU without a deal. If MPs reject both motions, Parliament will vote on 14 March to delay Brexit.