British Prime Minister Theresa May warned Saturday that the United Kingdom risks reversing its exit from the European Union if the country's two major parties fail to agree on a compromise withdrawal deal on time.

The prime minister said her Conservatives and the opposition Labour party had agreed on the need to end free movement for EU citizens in the UK, protect British jobs and leave the bloc with a deal.

"That is the basis for a compromise that can win a majority in Parliament and winning that majority is the only way to deliver Brexit," she said.

"The longer this takes, the greater the risk of the UK never leaving at all."

May began talks with Labour on a compromise deal earlier this week after a majority of lawmakers rejected her withdrawal agreement for a third time.

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Labour leader unimpressed

May's warning came hours after Labour chief Jeremy Corbyn said he had not "noticed any great change in the government's position" and that he was still waiting for May to budge on her previous "red lines" for any Brexit deal.

Yet May is planning to offer UK membership in a customs arrangement with the EU in an effort to win Labour support for a new deal, according to The Sunday Times newspaper.

The UK risks severe economic disruption if it crashes out of the EU on April 12 without a deal.

To avoid that outcome, May asked EU Council President Donald Tusk on Friday for an extension until June 30. EU leaders have however demanded that London first present a concrete plan for how it wishes to proceed before granting any extension. Tusk had suggested a year-long extension, before May's suggestion was made. 

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Summing up the mood in many EU capitals, German Foreign Minister Heiko Maas said "there are many questions that London must clarify" in this "difficult" situation.

Some EU leaders favor a longer extension on the condition that the UK takes part in European elections in late May.

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