After two previous rejections, the vote leaves Mrs. May’s deal in ruins and adds further confusion to the country’s politics, just two weeks before the scheduled departure date.

What’s next: The defeat appears to leave the increasingly weakened prime minister with two unpalatable options in the short run: Britain can leave the bloc on April 12 with no deal, a chaotic and potentially economically damaging withdrawal; or Mrs. May can ask European leaders — who have ruled out a short delay if her plan failed — for what could be a long postponement.

The gig economy arrives on Wall Street

Shares of Lyft, the ride-hailing company, opened for trading today at $87.24, above the public offering price of $72. At the I.P.O. price, Lyft had a market value of over $24 billion, making it one of the most valuable American companies to go public in the last decade.