MPs have voted to approve a historic bill that would legalise assisted dying in England and Wales.

The Terminally Ill Adults (End of Life) Bill was approved by 314 votes to 291 at its third reading in the House of Commons – a majority of 23.

Politics Live: MPs back legalising assisted dying in historic Commons vote

Labour MP Kim Leadbeater, who proposed the legislation, was seen crying in the chamber as it went through.

Campaign group Dignity in Dying hailed the result as “a landmark moment for choice, compassion and dignity at the end of life”.

“MPs have listened to dying people, to bereaved families and to the public, and have voted decisively for the reform that our country needs and deserves,” said Sarah Wootton, its chief executive.

The bill will now go to the House of Lords, where it will face further scrutiny before becoming law.

Due to a four-year “backstop” added to the bill, it could be 2029 before assisted dying is actually offered, potentially coinciding with the end of this government’s parliament.

The bill would allow terminally ill adults with fewer than six months to live to apply for an assisted death, subject to approval by two doctors and a panel featuring a social worker, senior legal figure and psychiatrist.

MPs have deliberated the proposals for months, with a vote in November passing with a bigger majority of 55.

Since then it has undergone some significant changes, the most controversial being the replacement of a High Court Judge’s approval with the expert panel.

Ms Leadbeater has always insisted her legislation would have the most robust safeguards of any assisted dying laws in the world.

Opening the debate on Friday she said that opposing the bill “is not a neutral act. It is a vote for the status quo”.

She warned that if her plan was rejected, MPs would be asked to vote on it again in 10 years and “that fills me with despair”.

The assisted dying debate was last heard in the Commons in 2015, when it was defeated by 330 votes to 118.

There have been calls for a change in the law for decades, with a campaign by broadcaster Dame Esther Rantzen giving the issue renewed attention in recent years.

Supporters have described the current law as not being fit for purpose, with desperate terminally ill people feeling the need to end their lives in secret or go abroad alone, for fear loved ones will be prosecuted for helping them.

Ahead of the vote, an hours-long emotionally charged debate heard MPs tell personal stories about their friends and family.

Maureen Burke, the Labour MP for Glasgow North East, spoke about how her terminally ill brother David was in so much pain from advanced pancreatic cancer that one of the last things he told her was that “if there was a pill that he could take to end his life, he would very much like to take that”.

She said she was “doing right by her brother” in voting for it.

How did MPs vote?

MPs were given a free vote, meaning they could vote with their conscience and not along party lines.

The division list shows Prime Minister Sir Keir Starmer voted in favour of the bill, but Conservative leader Kemi Badenoch voted against.

Health Secretary Wes Streeting and Justice Secretary Shabana Mahmood, who will have to deliver the bill, also voted no.

Read more: Find out how your MP voted

Bill ‘poorly drafted’

Opponents have raised both practical and ethical concerns, including that people could be coerced into seeking an assisted death and that the bill has been rushed through.

Veteran Labour MP Diane Abbott said she was not opposed to the principle of assisted dying but called the legislation “poorly drafted”.

Former foreign secretary James Cleverly echoed those concerns, saying he is “struck by the number of professional bodies which are neutral on the topic of assisted dying in general, but all are opposed to the provisions of this bill”.

Recently, the Royal College of Psychiatrists, the Royal College of Pathologists and the Royal College of Physicians have raised concerns about the bill, including that there is a shortage of staff to take part in assisted dying panels.

However, public support for a change in the law remains high, according to a YouGov poll published on the eve of the vote.

The survey of 2,003 adults in Great Britain suggested 73% of those asked last month were supportive of the bill, while the proportion of people who feel assisted dying should be legal in principle stood at 75%.

The assisted dying bill passed its third reading in the Commons with a majority of 23 and will now be passed to the House of Lords.

There were 314 votes in favour and 291 against.

In November, the bill passed its second reading by a majority of 55, more than twice as large as today. It then went to “committee stage”, during which the wording and implications were examined in detail, and tweaked with input from experts, stakeholders and the public.

Politics latest: Bill legalising assisted dying passed in the Commons

That amended bill will now be passed on to the House of Lords, where it will go through a similar process before being either passed back to the Commons with further amendments, or sent to the King for Royal Assent.

Only after both houses agree on the exact wording of the bill does it become law.

Who changed their vote since November?

A total of 56 MPs voted a different way today, compared to how they did in November. There were 11 who changed to yes, while 24 changed to no. There were also 21 MPs who voted last time who chose to abstain today.

Among those who chose to change their vote were foreign secretary David Lammy and culture secretary Lisa Nandy. Mr Lammy had voted against the bill in November, while Ms Nandy voted in favour. Both chose not to vote today.

Only one MP, Labour’s Jack Abbott, voted in favour today after voting against at the second reading.

Prime Minister Sir Keir Starmer has voted in favour of the bill on both occasions, as has Chancellor Rachel Reeves and former prime minister Rishi Sunak.

The health secretary, Wes Streeting, who will have a crucial role in implementing the legislation if it becomes law, has voted against the bill both times, as has Angela Rayner, the deputy prime minister, and opposition party leaders Kemi Badenoch and Nigel Farage.

Lib Dem leader Ed Davey voted against the second reading, but chose not to vote today.

The SNP again chose not to vote, as the bill will not apply to Scotland, but a majority of MSPs in the devolved Scottish parliament voted through similar proposals in its first stage last month.

They were among 43 MPs in total who did not vote this time, including the Speaker and his Deputies. That’s slightly lower than the 46 MPs who abstained during the second reading vote in November.

Overall, a clear majority of Labour MPs supported the bill, while most Conservatives voted against it.

What do the public think?

Pollsters YouGov asked people if they were in favour of assisted dying or against, before November’s second reading and again last month.

On both occasions, a majority said they approved of the policy becoming legal, both in principle and in practice.

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Vaults of enriched uranium and plutonium to make nuclear bombs are dotted about a secure site in Berkshire along with Anglo-Saxon burial mounds and a couple of lakes.

Surrounded by metal fences topped with barbed wire, much of the nuclear weapons facility at Aldermaston in Berkshire looks frozen in time from the 1950s rather than ready for war in the 21st century.

But a renewed focus on the importance of the UK’s nuclear deterrent means the government is giving much of its nuclear infrastructure a facelift as it races to build a new warhead by the 2030s when the old stock goes out of service.

Sky News was among a group of news organisations given rare access to the largest of Britain’s nuclear weapons locations run by AWE.

The acronym stands for Atomic Weapons Establishment – but a member of staff organising the visit told me that the public body, which is owned by the Ministry of Defence, no longer attributes the letters that make up its name to those words.

“We are just A, W, E,” she said.

She did not explain why.

Perhaps it is to avoid making AWE’s purpose so immediately obvious to anyone interested in applying for a job but not so keen on weapons of mass destruction.

For the scientists and engineers, working here though, there seems to be a sense of genuine purpose as they develop and ensure the viability and credibility of the warheads at the heart of the UK’s nuclear deterrent, this country’s ultimate security guarantee.

“It’s nice to wake up every day and work on something that actually matters,” said a 22-year-old apprentice called Chris.

Sky News was asked not to publish his surname for security reasons.

The workforce at AWE is expanding fast, with 1,500 new people joining over the past year.

The organisation has some 9,500 employees in total, including about 7,000 at Aldermaston, where the warhead is developed and its component parts are manufactured.

Designing and building a bomb is something the UK has not needed to do for decades – not since an international prohibition on testing nuclear weapons came into force in the 1990s.

It means the new warhead, called Astrea, will not be detonated for real unless it is used – an outcome that would only ever happen in the most extreme of circumstances as explained in a new podcast series by Sky News and Tortoise called The Wargame.

The last time, Britain test-fired a bomb was at a facility in Nevada in the US in 1991.

With that no longer an option, the scientists at AWE must rely on old data and new technology as they build the next generation of warhead.

This includes input from a supercomputer at the Aldermaston site that uses 17 megawatts of power and crunches four trillion calculations per second.

Another major help is a giant laser facility.

It is built in a hall, with two banks of long cylinders, lying horizontal and stacked one of top of the other running down the length of the room – these are part of the laser.

The beams are then zapped in a special, separate chamber, onto tiny samples of material to see how they react under the kind of extreme pressures and temperatures that would be caused in a nuclear explosion.

The heat is up to 10 million degrees – the same as the outer edge of the sun.

“You take all those beams at a billionth of a second, bring them altogether and heat a small target to those temperatures and pressures,” one scientist said, as he explained the process to John Healey, the defence secretary, who visited the site on Thursday.

Looking impressed, Mr Healey replied: “For a non-scientist that is hard to follow let alone comprehend.”

The Orion laser facility is the only one of its kind in the world, though the US – which has a uniquely close relationship with the UK over their nuclear weapons – has similar capabilities.

Maria Dawes, the director of science at AWE, said there is a sense of urgency at the organisation about the need to develop and then build the new bomb – which is a central part of the government’s new defence review published in early June.

“You’ve probably read the strategic defence review,” she said.

“There’s very much the rhetoric of this is a new era of threat and therefore it’s a new era for defence and AWE is absolutely at the heart of that and so a sense of urgency around: we need to step up and we need to make sure that we’ve got what our customer needs. Yes, there’s very much that sense here.”

It means an organisation that has for years been purely focused on ensuring the current stockpile of warheads is safe and works must shift to becoming more dynamic as it pursues a project that will be used to defend the UK long into the future.

In a sign of its importance, the government is spending £15bn over the next four years alone on the programme to build the new warheads.

Part of the investment is going into revamping Aldermaston.

Driving around the 700-acre site, which was once a Second World War airbase, many of the buildings were constructed into the 1950s, 1960s and 1970s.

The construction of new science and research laboratories is taking place.

But bringing builders onto one of the UK’s most secure nuclear sites is not without risk.

Everyone involved must be a British national and armed police patrols are everywhere.

No one would say what will be different about the new bomb that is being developed here compared with the version that needs replacing.

One official simply said the incumbent stock has a finite design life and will need to be swapped out.