MPs are debating further changes to the assisted dying bill including a ban on organisations advertising that they offer the service.
Other amendments being discussed cover regulations about which substances or devices may be used to facilitate a person’s death and the role of coroners in the process.
The bill would allow terminally ill adults with less than six months to live to receive medical assistance to die in England and Wales.
It was initially approved by MPs in November by a majority of 55 votes and has since been undergoing further scrutiny.
Since then at least a dozen MPs who backed it or abstained on the bill have said they are now likely to vote against it.
Supporters remain confident it will eventually clear the parliamentary hurdles and become law.
If the bill is approved at all stages in the House of Commons, it will then go to the House of Lords for further scrutiny.
The last time the bill was voted on, MP approved changes to ensure that no one would be forced to help with the process of assisted dying against their wishes.
Following concerns about an “anorexia loophole”, the House of Commons also accepted an amendment which stated that a person should not be eligible for an assisted death “solely as a result of voluntarily stopping eating or drinking”.
At the start of the debate, MPs agreed to an amendment on replacing doctors unwilling to assist in the process and another amendment which said there has to be a report from a doctor where there is concern about a proposed assisted death.
There was general consensus that assisted dying advertising should be prohibited, however there was disagreement about how strict the ban should be.
The amendment, tabled by the bill’s proposer Kim Leadbeater, gives ministers powers to make exceptions to the ban in the future, but fellow Labour MP Paul Waugh called for that power to be removed.
He told MPs: “One person’s advert is another person’s public information campaign. It’s not impossible to imagine a secretary of state in future who passionately believes in the merits of assisted dying to authorise such a campaign.”
Labour MP Tony Vaughan argued that Waugh’s proposal would remove “essential flexibility” allowing ministers to respond to future developments.
Conservative Rebecca Smith put forward an amendment which would ensure assisted deaths would still be investigated by a coroner.
Without that measure, she said it would be “exceptionally difficult to say whether there have been errors or instances of abuse”.
Disagreeing, Green MP Ellie Chowns said an assisted death under the provisions of the bill “would be the most scrutinised type of death in the country”.
“It makes no sense to require another legal process at the end of that when there have already been multiple layers of scrutiny,” she added.
If MPs have not finished discussing and voting on the amendments by 2:30 BST, another day of debate will be scheduled, probably on 20 June.
As with other stages of the process, protesters from both sides of the argument are expected to gather outside Parliament.
Disability campaigner George Fielding, from the Not Dead Yet UK campaign group, said the bill “risks state-sanctioned suicide”.
“It risks making people feel like a burden while ignoring the social, economic and systemic pressures that deny people the treatment and dignity they need to live.
In a letter to MPs this week, Labour’s Kim Leadbeater, said she was “confident” the legislation could be “the best and safest bill possible”.
