Prime Minister Theresa May has won approval from her parliament's lower chamber to trigger Britain's exit from the European Union, defeating attempts by pro-EU politicians to attach extra conditions to her plan to start divorce talks by March 31.
MPs voted 494 to 122 in favour of a law giving Ms May the right to start the formal Brexit process, ending days of intense debate which has tested Ms May's slim parliamentary majority.
The bill must now be approved by the upper chamber, in which Ms May does not have a majority, before it becomes law.
The victory marks a significant step towards starting what is expected to be a complex and difficult two-year negotiation with the EU on issues such as trade, immigration and security that will redraw Britain's role in the world.
"We've seen a historic vote tonight," Brexit minister David Davis said.
"A big majority for getting on with negotiating our exit from the EU and a strong, new partnership with its member states."
After surviving a minor rebellion from within Ms May's Conservative Party that had threatened to undermine her authority and negotiating strategy, the law was passed without amendment and on schedule.
That raised expectations the bill will enjoy an equally smooth passage in the unelected House of Lords, when its journey there begins in earnest on February 20 — the government wants to complete the legislative process by March 7.
Sources close to discussions in the upper chamber said they expected peers to keep pushing for parliament to have more say during the negotiating process.
One source said that could mean a one-week delay to the law's final approval, but neither expected the process to endanger Ms May's end of March deadline.