Exclusive: Starmer, then DPP, said it was not in public interest to prosecute Dr Michael Irwin after arrest in 2009

Dr Michael Irwin: ‘The majority of people want to change the law.’ Photograph: Martin Godwin/The Guardian

A doctor who was spared from criminal charges over assisted dying by Keir Starmer when he was director of public prosecutions has said he is sure the prime minister wants a change to the “ridiculous” laws on the issue.

Dr Michael Irwin was arrested in 2009 after reports that he had travelled to the Dignitas clinic in Switzerland with a terminally ill man and given him £1,500 towards the cost of ending his life.

After Irwin had been on bail for almost a year, Starmer announced that while there was sufficient evidence to prosecute him, it would not be in the public interest.

Irwin told the Guardian that his first thought when Starmer entered Downing Street was that a law on assisted dying might finally be passed. The 93-year-old said he was now hopeful “that the law will change in my own lifetime, so I don’t have to go to Switzerland myself” and that if his health deteriorated he wanted the option to die at home “in my own bed”.

Irwin’s comments come after three former heads of the Crown Prosecution Service gave their support for a bill to legalise assisted dying for terminally ill adults. Max Hill, Alison Saunders and Ken Macdonald all told the Sunday Times that they would be supporting a change in the law.

A bill on the issue was launched last week by Kim Leadbeater, the Labour MP for Spen Valley. Titled “choice at the end of life for terminally ill adults”, a debate and vote on it will be held on 29 November. The government is remaining neutral on the issue and Labour MPs will have a free vote.

Irwin travelled to Dignitas in 2007 with Raymond Cutkelvin, a Londoner who had an inoperable tumour of the pancreas and died at the Swiss clinic aged 58. Irwin was arrested two years later.

Announcing that the case was being dropped in 2010, Starmer, in his role as DPP, said Irwin had been “motivated by a strong belief that the law on assisted suicide is wrong” and that he “did not act for personal gain; did not put pressure on Mr Cutkelvin; and did not take an active part in the suicide itself”.

Irwin travelled to Dignitas on five occasions to help people end their lives. Only once did this result in arrest, he said, “and then dear Keir Starmer, who’s now the prime minister, decided that no further action should be taken because no jury would convict me”.

The retired GP had written to Starmer directly after his arrest, admitting to what he had done and inviting him to press charges for helping with a suicide, a crime that could result in up to 14 years in prison. But Starmer refused to pursue a prosecution, noting that Irwin was motivated “at least in part by personal sympathy”.

Irwin had previously been struck off the medical register in 2005 and received a caution for possessing a fatal dose of barbiturates that he intended to supply to a doctor friend.

While Irwin did not want to disclose a private conversation with Starmer at the time that his criminal case was dropped, he said: “I think he’s a very good person. A good person as prime minister and a good person as an individual. And I’m sure he wants to see the law change too.”

Of the decision Starmer made not to bring a charge, Irwin said: “​I thought he was a very sensible person who knew what the majority of people in this country would want for themselves, and it was a move in the right direction.”

Commenting on the way the law prevents people from helping those suffering with terminal conditions to end their lives, Irwin said: “The present situation is cruel, because people in that situation want as much help as possible and to be denied it is basically cruel.”

He added: “The present law is ridiculous. We know the majority of people want to change the law … I think it’d be very reassuring for people to know that it’s possible here and you don’t have to go to Switzerland.”

Irwin said he was still enjoying his life but wanted the option to end it if he was suffering with a terminal condition. “I’m now 93 years old. I have some difficulty in walking from an accident I had some years ago, but I don’t feel my age. I wake up in the morning thinking, my God, I’m this age and I don’t feel it. And I’m pretty active. I go out to restaurants, go up to London, but it’d be nice to have that option when the time comes.”

The archbishop of Canterbury warned last week that legalising assisted suicide could result in “intense and inescapable” pressure on people to end their lives early. Justin Welby wrote in the Daily Mail that “the right to end your life could all too easily – and accidentally – turn into a duty to do so.”