A retired neurosurgeon with advanced prostate cancer has backed calls from a cross-party group of more than 50 MPs and Peers for the Government to instigate a review of the UK’s assisted dying laws.

Dr Henry Marsh, who is also an author, said he believed that if people in his situation were able to “choose how, when, and where they would die” this would “greatly reduce their suffering”.

His comments come alongside a joint letter from parliamentarians to Justice Secretary Robert Buckland which argued the UK was “falling behind the rest of the world”.

The letter, coordinated by Humanists UK and campaign group My Death, My Decision, claimed that “our laws on assisted dying are letting down our citizens”.

The letter comes after paralysed former builder Paul Lamb lost a bid to challenge the law on the issue.

Mr Lamb, who previously lost a right-to-die case in the Supreme Court in 2014, had asked the Court of Appeal to allow a fresh challenge of the law on assisted dying to go ahead after being refused permission by the High Court in December 2019.

Lawyers for Mr Lamb argued the current law, which bans assisted suicide under threat of up to 14 years’ imprisonment, is discriminatory and breaches his human rights.

But the bid was rejected by a Court of Appeal judge in May 2020.

The joint letter said that Mr Lamb’s loss meant there was likely to be “no further litigation” and the matter was “firmly one for Parliament to resolve”.

It added: “It has now been half a decade since Parliament examined legislation on assisted dying, and 15 years since it formally scrutinised the issue via Lord Joffe’s Select Committee.

“In these years, the evidence has materially changed, and that new evidence necessitates a fresh review.”

The letter, signed by members of the Conservatives, Labour, Liberal Democrats, SNP, Green Party, and crossbenchers, claimed there had been “a significant shift in professional medical opinion and within the disability community”.

It claimed that the organisations Parkinson’s UK, the Multiple Sclerosis Society, and the Motor Neurone Disease Association “have adopted neutral stances on this important issue”.

The letter also said Canada, Germany, Italy, New Zealand, and parts of the United States and Australia “have changed or are due to change their law since 2015” while “several other nations, including Ireland, are actively considering similar proposals, reflecting that such changes can be achieved in a safe and compassionate way”.

It continued: “We recognise that there are weighty and legitimate concerns about changing the law on assisted dying, and do not want to shy away from these challenges.

“However, an inquiry or call for evidence would present the best opportunity to explore these difficult questions in an objective and sensitive way.”

Dr Marsh, 71, who is retired from the NHS, said: “Having spent a lifetime operating on people with cancer, the prospect of dying slowly from it myself fills me with dread.

“Despite the best efforts of palliative medicine, I know that dying from cancer can still be a very horrible business – for both patient and family, despite what the opponents of assisted dying claim.

“I fiercely believe that if people in my situation knew they had the ability to choose how, when, and where they would die, it would greatly reduce their suffering.”

He said current law does not allow for such “comfort”, adding that it “insists instead that I must suffer”.

Dr Marsh added: “Many politicians have shown a striking lack of compassion by ducking this issue for too long, and are inadvertently guilty of great cruelty.

“Irrespective of your view on assisted dying, I would hope everyone could agree that our laws should be based on evidence and informed decisions, not alarmist, unfounded opposition that flies in the face of all the evidence from countries where assisted dying has been legalised.

“It’s time for all MPs to start taking this issue seriously and I urgently call upon them to undertake an inquiry into the law.”

Humanists UK’s chief executive, Andrew Copson, said: “In coming together to demand an inquiry, Henry and the lawmakers who have signed this letter have put the voices of the terminally ill and incurably suffering at the centre of the debate.”

Conservative MP Crispin Blunt, co-chair of the All-Party Parliamentary Humanist Group, who has signed the letter, said: “MPs owe their constituents a duty of compassion not to let the suffering of those who are terminally ill or incurably suffering go unnoticed.”