Sir Keir Starmer said he is pleased he could keep his vow to Dame Esther Rantzen to make time for a debate and vote on assisted dying as a Bill is set to come before Parliament this month.

The broadcaster, who is terminally ill and has been outspoken in her calls for change, said she was not expecting to have a chance to witness such a debate in her lifetime and that the news has filled her with hope.

Dame Esther had a telephone conversation with Sir Keir earlier this year – before he became Prime Minister – in which he pledged his commitment on the issue.

On Thursday, it was announced that Labour MP Kim Leadbeater will introduce a private member’s bill (PMB) on assisted dying after topping a ballot, which gives her priority on a Friday sitting.

It is expected to be formally introduced on October 16, with a debate and initial vote on the matter possible within weeks.

It will be the first time the topic has been debated in the House of Commons since 2015, when an assisted dying Bill was defeated.

Ms Leadbeater said she hoped for “honest, compassionate and respectful debate” on her Bill, which would establish in law the right for terminally ill eligible adults to have choice at the end of life to shorten their deaths and ensure stronger protections for them and their loved ones after.

Speaking on Friday, Sir Keir said: “I’m very pleased that I’m able, as it were, to make good on the promise I made to Esther Rantzen.

“The Government will be neutral on this as you know, but I did make that commitment to a free vote and I am sticking to that commitment.”

Dame Esther, who revealed in December that she has joined the Swiss Dignitas clinic, told BBC Radio 4’s Today programme: “The fact that I may actually still be here to witness a debate in Parliament on this crucial life and death issue is not what I expected at all.

“It fills me with hope but it also fills me with fear.”

(The Bill) will not undermine calls for improvements to palliative care. Nor will it conflict with the rights of people with disabilities to be treated equally

MPs debating and eventually voting on a Bill have a “heavy responsibility”, Ms Leadbeater acknowledged, but she added that doing nothing would “leave too many people as they come to the end of their life continuing to suffer in often unbearable pain and fear of what is to come, denied the choice they deserve”.

She has pledged to consult widely about the details of her Bill, and sought to assure the public that it will not – as some campaigners have argued – pressure people to have an assisted death against their will.

She added: “It will not undermine calls for improvements to palliative care.

“Nor will it conflict with the rights of people with disabilities to be treated equally and have the respect and support they are absolutely right to campaign for in order to live fulfilling lives.

“I support these causes just as passionately.”

Cabinet Secretary Simon Case wrote to ministers to state that the Government will “remain neutral on the passage of the Bill and on the matter of assisted dying”.

He said ministers “need not resile from previously stated views when directly asked” but “should exercise discretion and should not take part in the public debate”.

Sir Keir has previously said he is “personally in favour of changing the law” and supported a change the last time the issue was voted on in the Commons nine years ago.

Energy Secretary Ed Miliband described the current law as “cruel” and said he intends to back the Bill, as he has done in the past.

He told ITV’s Good Morning Britain: “Obviously, there have to be proper safeguards and I understand the concerns of some people on these issues, but my personal view will be to vote in favour of this Bill.”

I would strongly urge the Government to focus on fixing our broken palliative care system that sees up to one in four Brits who would benefit from this type of care being unable to access it, rather than discussing again this dangerous and ideological policy

Elsewhere, Liberal Democrat leader Sir Ed Davey said he would be voting against the Bill.

He told the PA news agency: “I personally voted against it last time and I expect to do this time, but it is a free vote and there will be lots of Liberal Democrat MPs who will vote the other way and that is absolutely fine, because it is an issue of conscience here.”

Sir Ed drew on his experience of looking after his terminally ill mother as a teenager, and said he would rather see improvements to end-of-life care.

“I think if people knew that the palliative care was better, many of them wouldn’t support this legislation,” he added.

Dr Gordon Macdonald, chief executive of Care Not Killing which is opposed to a change in the law, said the Bill’s introduction was “clearly disappointing news”.

He said: “I would strongly urge the Government to focus on fixing our broken palliative care system that sees up to one in four Brits who would benefit from this type of care being unable to access it, rather than discussing again this dangerous and ideological policy.”

Assisting someone to end their life is against the law in England, Wales and Northern Ireland and while it is not a specific criminal offence in Scotland, assisting the death of someone can leave a person open to being charged with murder or other offences.

A Bill is currently being considered at Holyrood that, if passed, would give terminally ill adults in Scotland the right to request help to end their life.

Ms Leadbeater’s Bill would cover England and Wales only.

Former Labour justice secretary Lord Falconer of Thoroton has introduced the Assisted Dying for Terminally Ill Adults Bill in the House of Lords, which is expected to be debated in mid-November.