The first “citizens’ jury” on assisted dying in England has backed a change in the law to allow people who are terminally ill to end their life.

A jury of 28 people concluded it should be an option for those judged to have capacity to make their own decisions.

While it has no legal powers, the Nuffield Council on Bioethics, which set up the jury, said it represented a crucial new piece of evidence in the debate as it allowed the public to consider the issues more deeply than they could in surveys.

However, campaigners questioned the validity of the exercise, as a majority of those recruited were already in favour of changing the law.

Dr Gordon Macdonald, of the Care Not Killing campaign group, said: “A jury in a court of law must be rigorously impartial with no strong views about the case they are judging.

“So, what could have been a serious contribution to this important debate seemingly fails the impartiality test.”

However, Nuffield Council on Bioethics director Danielle Hamm said that in such a “highly complex, sensitive and ethically charged” debate as assisted dying, a citizens’ jury allowed more in-depth consideration to be given to the issue, as well as exploring the reasons for people forming their views.

The council said it had set up the jury because of the growing interest in the issue.

Prime Minister Sir Keir Starmer supports a change in the law in England and has committed to holding a vote on it.

A bill proposing changing the law in Scotland is due to be debated in the autumn.

Meanwhile, politicians in Jersey and the Isle of Man have already backed plans to introduce assisted dying.

The jury spent eight weeks listening to experts and campaigners and reviewing evidence.

It was drawn up to be representative of the general public, both in terms of demographics and age as well as attitudes to assisted dying. This meant a majority – 17 – of those who took part were in favour of assisted dying at the start, in line with polling.

Alongside asking them whether they wanted to see a change in the law, the jury was also asked why.

Of the 28 who voted, 20 ended up backing assisted dying at the end, with seven against it. One person remained undecided. Members of the jury changed their views both ways.

The jury supported both physician-assisted suicide, where the health professional prescribes lethal drugs for eligible patients to take themselves, and voluntary euthanasia, where a health professional administers the drugs to the patient.

The most common reasons for backing a change were to stop people living in pain at the end of their lives, giving people the knowledge they can die with dignity, and the importance of allowing people options and choice.

However, concerns were expressed that a new right to assisted dying could lead to it being misused if the right safeguarding was not put in place and could lead to a loss of funding for end-of-life care.

Ashok, 53, a social worker who took part in the citizen’s jury, said he was “on the fence” when the process started, but had been convinced by the evidence put forward to vote in favour of changing the law.

“You need safeguards to protect the vulnerable and stop abuse. But when we heard the evidence and considered the experience of those who have suffered at the end of their life I felt it was time to give people options.

“The jury was really challenging, it was upsetting at points, but it made us really think about the issue deeply.”

Assisted dying is already allowed in some US states, Australia and parts of Europe.

Sarah Wootton, chief executive of campaign group Dignity in Dying, said the results showed the “clear strength of public opinion”.

“It’s clear that when people are given time to look at this issue in-depth, examine all the evidence and hear different perspectives on the debate, they continue to overwhelmingly support change.

“It is inarguable that the public wants this reform to happen.”