British lawmakers on Friday approved plans to introduce medically assisted dying for terminally ill patients in England and Wales, advancing what would be one of the biggest social changes seen in Britain in decades.

After a debate that was at times emotive and fraught but remained respectful in tone, legislators supported the proposal by a vote of 314 to 291.

The vote on Friday was the second time lawmakers have approved the idea of medically assisted dying, after an initial vote in November was followed by months of scrutiny and debate in parliamentary committees. The issue has provoked deep division in and beyond the British Parliament.

The bill now goes to the unelected second chamber of the Parliament, the House of Lords. While the Lords can amend legislation, the fact that the bill has the support of elected lawmakers means that it is very likely to become law.

That would mean Britain would join a number of jurisdictions where assisted dying is permitted, including a small number of European countries, Canada and New Zealand, as well as 10 U.S. states and the District of Columbia.