THE MP behind the assisted dying Bill has insisted it is taking “absolutely the right route” through Parliament after it was criticised as an “utterly inadequate” way to deal with the controversial issue.

Kim Leadbeater defended the level of scrutiny her Terminally Ill Adults (End of Life) Bill will get after a group of MPs mounted a bid to halt the plans going through the Commons.

The Bill is due to have a five-hour debate on Friday – the first such debate in the Commons on the issue in almost a decade – with a vote expected at the end on whether it should pass through to be scrutinised by a committee.

Meanwhile, it has been confirmed that former prime ministers Liz Truss, Boris Johnson and Baroness Theresa May all oppose the Bill.

None of them will have a vote on Friday but Baroness May would if the Bill reached the Lords.

Former prime minister Gordon Brown last week voiced his opposition to the legislation, insisting the focus should be on better end-of-life care.

An amendment revealed on Tuesday, backed by six cross-party MPs, raised concerns about the level of debate and scrutiny before any vote on Friday, and called for an “independent assessment” of the provision of palliative care.

The amendment would “decline” to give a second reading to the Bill but whether or not it is voted on would depend on whether it is selected by the Speaker.

Ms Leadbeater said the development was “disappointing”.

She told BBC Radio 4’s Today programme: “The route of the private member’s bill is absolutely the right route for taking this legislation through. That means that there can be a free vote by all MPs. It is not a Government Bill.

“The Government has a neutral position on this and, sadly, the amendment that a handful of MPs have put forward is disappointing in that the public clearly want this debate to take place, and I think we’ve got responsibilities as parliamentarians to make sure that that debate does take place.”

Liberal Democrat MP Munira Wilson, who is backing the amendment, told the PA news agency that she is “concerned about the process or lack thereof” over what could be a “monumental change in legislation”.

Ms Leadbeater said the debate on assisted dying generally “has been going on for decades”, and she believes “this Bill will receive more scrutiny and more discussion and more debate, probably, than any piece of legislation”.

Ms Leadbeater also said the role of High Court judges in any assisted dying process under her Bill is “really, really important” and not a rubber-stamping exercise.

This followed comments from a former Lord Chief Justice, Lord Thomas of Cwmgiedd, who said this week that “no-one has grappled with the detail” of the impact that assisted dying legislation could have on the court system.

Ms Leadbeater said while it would be a new area of work for judges, they are “used to making these difficult and complex decisions and being part of this process”, citing current procedures around decisions on turning off life support machines for terminally ill people.

She also described the term “assisted suicide”, used by some campaigners opposed to a change in the law, as “quite offensive to some people”.

She added: “This is not people who want to end their lives, it’s people who are dying. And we have to think about that, and that’s why it’s about ‘assisted dying’.”