The result of the assisted dying vote is on a knife edge.

No one in Westminster really knows which way it will go.

But why is that so?

A vote on euthanasia was supposed to be one of the easiest reforms to Keir Starmers government.

The last time MPs voted on it in 2015, they overwhelmingly rejected it.

However, public opinion has changed dramatically over the past seven years.

New figures from the YouGov poll indicate that more than seven in ten people agree with the principle that assisted dying should be legal.

And a recent Daily Express poll found that eight out of 10 readers supported a change to the law.

For many, a law allowing terminally ill patients to choose to die would be a progressive and historically significant change.

So why will the November 29 vote be so close?

The problem ultimately lies with Sir Keir.

Aware of the complexity of the issue, the Prime Minister did not want to have to order his MPs to vote for euthanasia.

His strategy was instead to use a private member’s bill, devised by Labor backbencher Kim Leadbeater.

But the ploy didn’t work as a strong opposition has emerged, and there is no guarantee the bill will pass on Friday.

The magic number to win the vote is around 320, less if some MPs abstain.

As it stands, Expressen understands that at least 250 members of parliament will vote for.

About 100 are believed to waver in both directions.

Labor and the Lib Dems have more MPs publicly pro, while Tories have more public against.

To make matters worse for Starmer, the bill’s main critic is not from the opposition benches but from his own side, Health Minister Wes Streeting.

Streeting has not only said he will vote against, but that he is doing so because he fears the bill could damage existing health services.

His very public interventions in recent weeks have provoked a furious backlash, including from Labour.

The Health Secretary initially said that palliative care on the NHS was not good enough to guarantee people a fair choice.

He also raised concerns about the potential drain on NHS resources and ordered officials to assess the likely cost.

And has highlighted fears that some people could feel pressured to end their own lives to avoid becoming a burden to their loved ones – something he described as a “chilling slip”.

Labour’s former deputy leader Harriet Harman accused Streeting of “crossing the line” by suggesting his department was opposed to the move.

Leadbeater described his comments as “quite disappointing and quite upsetting”.

The Prime Minister is reported to have personally reprimanded Streeting in private for not staying out of the debate.

Starmer’s views on the matter are quite clear as he has a long history of supporting the decriminalization of assisted suicide.

Last year he said there were “reasons to change the law” on the issue.

In March this year, he promised campaign leader Dame Esther Rantzen he would make time for a free vote if Labor won the election, saying he was “personally in favor of changing the law”.

But some have accused him of “backing off” from the debate while Streeting takes the lead.

A Labor source said the Prime Minister’s “lack of leadership” had “created a vacuum” for those who want to stop the change from happening.

“This could end quite embarrassingly for the Prime Minister, which is not what he needs after the last few months,” they said.

Others have accused Sir Keir of being spineless on the issue.

“Like many things, he just likes to see how the wind blows and go with it. Streeting has been allowed to publicly speak his mind and influence the undecided.”

The split in the Cabinet over the issue has also deepened – with Education Secretary Bridget Phillipson suggesting she would vote against a change to the law.

Meanwhile, Transport Secretary Louise Haigh said she intended to vote for a change to the law.

Justice Minister Shabana Mahmood said last month she will not support the bill, while Culture Secretary Lisa Nandy has said she will vote yes.

Chancellor Rachel Reeves last week declined to give her opinion, saying she will “look at all the evidence ahead of the vote in Parliament”.

Home Secretary Yvette Cooper has also suggested she may support it.

Kit Malthouse is one of the most senior Tory MPs to publicly state that he is in favor of assisted dying.

Conservative leader Kemi Badenoch has said she is supportive in principle but has reservations about whether the change can be implemented within the current system.

Many of those opposed to a law change have expressed concern about the potential for coercion and mandate creep, saying the legislation has been rushed.

But advocates argue that existing legislation lacks proper safeguards, fails to respect patient autonomy and economically discriminates between those who can afford to travel abroad to end their own lives within the law and those who cannot.

Leadbeater has described his Bill as the most “robust” in the world, with “three layers of scrutiny” in the form of a sign-off by two doctors and a High Court judge.

It would also make coercion a crime with a possible sentence of 14 years in prison.

The Terminally Ill Adults (End of Life) Bill is supported by the Daily Express Give us our last rights crusade and Dame Esther.

The campaigner, 84, has registered with Dignitas after being diagnosed with stage four lung cancer last year.

The bill, which covers England and Wales, says only terminally ill adults with less than six months to live and an established wish to die would be eligible.

Another reason for the tension is the genuine philosophical debate.

Campaigners on both sides of the assisted dying debate are fiercely lobbying MPs and hosting events in Westminster.

Humanists UK this week hit out at Christian Action, Research and Education for encouraging people to write to their MPs using an online template that does not mention religion.

It comes after an investigation found that some opposition groups presenting themselves as grassroots campaigns were funded by conservative Christian pressure groups.

If successful, further debates and votes would be needed before the bill becomes law.