May has come under pressure from lawmakers, businesses and investors to set out at least a broad picture of how she sees Britain's future relationship with the EU. She says giving too much away could weaken Britain's hand in the country's most important negotiations since World War Two.
After a sometimes rowdy session in parliament, lawmakers voted by 448 to 75 to support a motion calling on the government to offer up its Brexit plan, but also backed the government's timetable to trigger the divorce procedure by the end of March.
During the six-hour debate, the opposition Labour Party pressed its motion for a plan setting out the government's negotiating stance in its talks with the bloc, before Article 50 of the EU's Lisbon Treaty is invoked to start the exit process.
But by agreeing to the government's demand for parliament to endorse May's timetable for Article 50, Labour lawmakers were accused of falling into a trap -- allowing ministers to begin the divorce without consultation.
Labour Brexit spokesman Keir Starmer denied the vote was on Article 50. It was a vote, he said, to force the government to offer a plan with "enough detail and clarity to end the circus of uncertainty" over Britain's future ties to the EU's single market of 500 million consumers.