France's lower house of parliament has approved a right-to-die bill at its first reading.
It is the first step in a lengthy process to grant medical assistance to people to end their lives in clearly defined circumstances.
A total of 305 members voted in favour of the legislation, which has the backing of President Emmanuel Macron, but is contested by some conservative groups.
Some 199 deputies in the lower house did not support the bill.
It will now pass between National Assembly and the Senate for modifications that are acceptable to both houses.
President Emmanuel Macron has said that he could put the deeply divisive topic to a referendum.
He described the outcome of the vote as "an important step" on "the path of fraternity".
"The National Assembly's vote on legislation concerning the development of palliative care and assisted dying is an important step," President Macron said on X.
"With respect for sensitivities, doubts and hopes, the path of fraternity that I hoped for is gradually opening up."
Mr Macron has insisted that any authorisation to choose death should be limited to people with incurable illnesses and intense physical or psychological pain.
If approved, France would join a small group of European countries that give the right to aid in dying, including Germany, Spain, Austria and Switzerland.
Until now, French patients wishing to end their lives have had to travel abroad, including to neighbouring Belgium.
A separate bill, submitted at the same time and concerned with end-of-life medical assistance, including palliative care, was passed without opposition.
All parties in parliament have allowed their members a free vote on the issue.
Leftist and centrist groups were expected to vote in favour of the right-to-die bill, with conservatives and far-right deputies seen as broadly hostile.
The legislation is widely referred to as focusing on "end of life" or "aid in dying" in the French debate, rather than "assisted suicide" or "euthanasia".
The bill, introduced by Olivier Falorni, an ally of President Macron, would allow medical staff to help "a person gain access to a lethal substance when they have expressed such a wish".
The patient would use the substance without aid or have it administered by a medically qualified person "if they are in no condition physically to do so themselves".
Health Minister Catherine Vautrin said at the weekend that the "French model" of assisted dying would be "strict and closely supervised".
Last year, Mr Macron said that France needed legislation in this area because "there are situations you cannot humanely accept".
The goal was "to reconcile the autonomy of the individual with the solidarity of the nation", he added.
The bill faces stiff opposition from religious leaders in a country with a longstanding Catholic tradition, as well as many health workers.
Prime Minister Francois Bayrou, a devout Catholic, said that he would abstain if he were a deputy because of lingering "questions".
The draft law would allow assisted dying only in an "advanced" stage of illness, which it defines as "entering an irreversible process characterised by a worsening health condition of the sick person that affects the quality of their lives."
Current French legislation allows passive euthanasia, such as withholding artificial life support and, since 2016, doctors have also been authorised to induce "deep and continuous sedation" for terminally ill patients in pain.
However, active euthanasia, where doctors administer lethal doses of drugs to patients, remains illegal.
Ms Vautrin said that she hopes the Senate will begin examining the issue this year and submit its suggested changes to the National Assembly in early 2026.
"I want this bill to get a final vote by 2027 which is still possible," she said.
France holds presidential elections in 2027 in which Mr Macron cannot stand after serving two consecutive terms.
