Macron had promised such a law when he was re-elected for a second term in 2022, in a change seen as one of the most important social reforms since France allowed same-sex marriage in 2012. 

If the country's highest constitutional authority approves the legislation, France will join the Netherlands, Belgium, Switzerland and Canada in legalising assisted dying. 

"In 2022, I made a commitment to open this path with the French people," Macron wrote on X.

"With seriousness, humility, and in full respect of our democracy, that commitment has been honoured."

The law establishes a right to assisted dying for some adults suffering from an incurable condition. 

They must be capable of expressing themselves in a "free and informed" manner and be suffering from physical pain. 

This pain must either be unresponsive to treatment or, in the patient's view, unbearable, where they have chosen not to receive or to stop receiving treatment.

A physician is responsible for verifying the patient's eligibility, before a panel assesses the criteria.

Ultimately, the doctor makes the decision alone, and the patient may withdraw consent at any time.

The patient will administer a lethal substance themselves, with exceptions for those who are physically unable to be helped by a health worker.

'Historic'

Jonathan Denis, of the the Association for the Right to Die with Dignity, said more battles remained to be waged but it was a "historic moment".

Lawmakers applauded the bill's author Olivier Falorni, a former lawmaker-turned-mayor, after what he has described as years of battle in parliament.

"Many patients passed away before they had access to this right. My thoughts go out to them, to their loved ones, to their families," Falorni told the lower house.

The law had easily passed the National Assembly but was rejected by the Senate upper chamber, with the government allowing the lower house to have the final say without the Senate's assent, as permitted by the constitution.

Prime Minister Sebastien Lecornu has asked the Constitutional Council to examine the new legislation.

His office said it was called in after the lack of debate in the right-leaning Senate meant the text fell short of a draft "meeting both the aspirations of its proponents and the concerns of those worried about its implementation".

The council, whose rulings are binding, can in extreme cases declare an entire piece of legislation invalid or express reservations about certain sections.

Right-wing heavyweights from the traditional right Republicans party that dominates the Senate, such as speaker Gerard Larcher and former interior minister Bruno Retailleau, have staunchly opposed the legislation.

'Diabolical'

Brigitte Liso, a lawmaker from the president's centrist Renaissance party, told the assembly she was proud to take part in passing the law.

"Proud because one day I will be able to say to my grandchildren: 'I was there'," she said.

But Justine Gruet, a Republican, said it would be remembered as "the day the French parliament decided that a human life could be legally ended".

"History will judge us," she added.

After allowing same-sex couples to marry in 2012, France in 2024 became the first country in the world to enshrine the right to terminate a pregnancy in its constitution. 

Outside parliament, Emmanuel Delhoume, Orthodox Christian cleric, was among those protesting the bill.

"I can neither condone abortion, nor marriage for everyone, nor euthanasia," he told AFP.

"It's a diabolical chain" of events.

Elsewhere in Europe

In the Netherlands, euthanasia has been legal but strictly regulated since April 2002. 

A doctor and an independent expert must determine that the patient is suffering unbearably and without hope of improvement. 

This right was extended in 2023 to children under 12. 

Belgium followed the Netherlands later in 2002 by adopting euthanasia with similar caveats to the Dutch. 

In 2014 it became the first in the world to allow terminally ill children of all ages to also request euthanasia. 

Luxembourg decriminalised euthanasia and assisted dying in 2009.

Switzerland prohibits euthanasia but has allowed assisted dying since World War II, its criminal code outlawing its incitement or assistance only "from selfish motives".

Medical ethics codes are in place and the patient is helped to die by associations. Many Europeans go there to be helped to die.

The parliament in neighbouring Austria also voted to legalise assisted dying for those with a serious or terminal illness in 2021.

Spain adopted a law in 2021 allowing euthanasia and medically assisted dying.

The conditions are strict: the applicant must be capable and conscious, the request must be made in writing, reconfirmed later, and approved by an evaluation committee. 

The Slovenian parliament in July last year legalised assisted dying for lucid, terminally ill patients if their suffering was unbearable and all treatment options had been exhausted.

But Slovenians in a November referendum voted to suspend the law.

Portugal adopted the decriminalisation of euthanasia in 2023, but the Constitutional Court last year decided it should not come into force.

In Italy, the Constitutional Court outlined the conditions under which a patient could access assisted dying without the helper facing criminal charges in 2019. 

But it remains difficult to apply as the Italian parliament has not adopted the necessary legislation.

As a result, a pro-euthanasia association pushed for the adoption of regional rules, with Tuscany being the first last year to speed up and simplify the procedure.

Prime Minister Giorgia Meloni's right-wing coalition challenged Tuscany's regulation. 

UK lawmakers will again debate legalising assisted dying in September.

Members of the House of Commons last year voted to allow adults with an incurable illness to take substances that cause their death in England and Wales, but the unelected upper house scuppered the bill.

Lawmakers in the self-governing British dependencies of Jersey and the Isle of Man have already approved euthanasia legislation, but the moves are still awaiting royal assent.

Lawmakers in Edinburgh in March rejected a bill in the devolved Scottish parliament to legalise assisted dying.