(Bloomberg) -- Boris Johnson is sending the letter to Brussels he never wanted to write.

Bound by a law passed by opposition Members of Parliament, he will formally ask the European Union to delay Brexit until Jan. 31, according to a person familiar with the matter. At the same time, he pledged to push on with his plans to leave by his Oct. 31 deadline.

Johnson spoke to European Council President Donald Tusk this evening and confirmed that the letter would be sent before tonight’s deadline, an EU official said. Tusk will then start consulting EU leaders on how to react, which may take a few days. A unanimous vote is required to grant an extension.

After Saturday’s defeat in Parliament, Johnson never got his chance to see if MPs would support his deal. He now plans to push through the legislation in less than two weeks. The Withdrawal Agreement Bill could begin its journey as soon as Tuesday, after Johnson makes another attempt on Monday to get Parliament to sign off on the principle of his deal, making the extension unnecessary.

If he succeeds, he will be able to meet the deadline and then push for a general election. If he fails, he risks plunging the country into a political crisis that could see Brexit delayed and the country vote once again on its EU membership.

Based on how MPs voted today and their comments during the debate, Johnson might still have a chance. It could come down to a single vote.

To contact the reporters on this story: Tim Ross in Brussels at tross54@bloomberg.net;Ian Wishart in Brussels at iwishart@bloomberg.net

To contact the editors responsible for this story: Heather Harris at hharris5@bloomberg.net, James Ludden

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