The 432-to-202 vote on Tuesday was the biggest defeat in the House of Commons for a prime minister in modern history. Here are the key takeaways.

What’s next: Mrs. May has until Monday to present a backup plan, but European Union officials had said the deal that Parliament rejected was the only one they would accept. We outline the possible outcomes, including a second referendum or a chaotic “no-deal” exit.

News analysis: Much of Mrs. May’s Conservative Party voted against the deal. Her struggle may signal the end of Britain’s “elective dictatorship” and the start of a gridlock-prone system.

Catch up: What is Brexit, and what does it all mean?