British lawmakers backed a proposal to legalize medically assisted suicide in a historic and contentious vote on Friday — mirroring debates on the other side of the Atlantic as legal and political issues are playing out in America over the procedure.

In the first House of Commons vote on the issue in nearly 10 years, MPs backed the bill 330 to 275. The bill won’t immediately become law — it instead moves forward to be scrutinized and possibly amended by parliamentary committees before a third reading vote — but the initial approval of the legislation marks a significant cultural shift in the country.

The Terminally Ill Adults (End of Life) Bill would allow terminally ill adults with decision-making capacity to end their own lives with a doctor’s assistance, as long as the patient is expected to have six months or less to live. The measure specifies that the patient must be a resident of England and Wales and defines terminally ill as an “inevitably progressive illness, disease or medical condition which cannot be reversed by treatment.” It also specifies that people with a mental disorder or disability alone are not considered to be terminally ill.

The topic of assisted suicide has sparked passionate debate in the United Kingdom and beyond, as backers of it say that the procedure is a compassionate way for people with terminal illnesses to end their pain with dignity, surrounded by loved ones. Opponents, including many religious leaders, argue that there could be unintended harms from legalizing it, including vulnerable groups believing that they are a burden and feeling pressured to die. They also suggest a potential “slippery slope,” pointing to places like Canada, where the practice has been gradually expanded and has led to shockingly high death tolls.

“I’ve seen the pain in the eyes of relatives who want to ease the suffering of their dying loved ones,” one MP, Dr. Kieran Mullan, said on Friday before the vote. “But I’ve also held the hand of frail elderly people, forgotten by their families, feeling themselves to be nothing but a burden.”

He said that from his time working as a doctor, he’s sympathetic to both sides of the argument and that there’s not a perfect choice but rather “different versions of imperfection.”

“Some people may not want to spend their final days in a drug-induced state of semi-consciousness to manage their pain,” he said. At the same time, he added, “If this law is passed, it would represent the crossing of a significant legal, societal, and moral Rubicon.”

“Every other expectation we have of the state is to help extend and protect life,” he added. “We would instead be asking the state to procure the medicines, provide the staff, and sign off through the courts, a process that is designed to and will lead to someone’s death.”

Britain’s debate comes as assisted suicide in America has been legally fraught on the state-level, despite polling indicating that the public generally favors it being legal. Seven in 10 Americans support euthanasia — allowing doctors to “end the patient’s life by some painless means if the patient and his or her family request it,” Gallup polling shows.

A majority — 66 percent — also support allowing doctor-assisted suicide, in which the patient commits the act themselves with the aid of a doctor. Views on whether the practices are moral are “more mixed,” Gallup indicates, with 53 percent saying that the procedure is morally acceptable while 40 percent believe it’s morally wrong.

Assisted suicide is currently legal in nine states and Washington, D.C., and lawmakers are considering legalizing it in New York and Michigan. In New Jersey, where the practice is legal, a federal lawsuit is pending over the state’s residency requirement after a Delaware woman and physician challenged it, arguing that residency rules are unconstitutional. If the challenge is successful, and New Jersey’s residency requirements are removed, it’s expected to expand access to assisted suicide to millions of people in the heavily populated states bordering New Jersey.