A GP who admitted giving lethal doses of painkillers to his patients has called for a national debate on euthanasia, saying it is already common practice in hospitals.

But Dr Howard Martin, the former County Durham GP, who learnt this week that he will not face a second trial for the murder of three patients, has called on others to lead the discussion, saying he now wants a quiet life.

His comments were last night criticised by the families of the dead patients. They accused him of trying to hurt them by speaking out.

The families will now consider whether to take civil action against him. In 2005, Dr Martin was acquitted of murdering three patients, Harry Gittins, 74, Frank Moss, 59, and Stanley Weldon, 74, with morphine overdoses while working as a GP in Newton Aycliffe, County Durham.

The investigation was reopened by Durham Police after he claimed in the press last June that he had acted out of “Christian compassion”.

However, Durham Crown Prosecution Service announced this week that there was not enough new evidence for the doctor to be re-tried.

Speaking from his home in Wales yesterday, Dr Martin told The Northern Echo that giving morphine to terminally- ill patients in hospital to end their lives was a regular occurrence.

He said he served for 20 years in hospitals before becoming a GP, saying: “It’s accepted, but when I did the same as a GP I got put in prison – I’ve never seen a hospital doctor put in prison.”

He said patients were suffering unnecessarily because doctors were afraid to carry morphine.

“Some of the doctors are not carrying morphine with them, so they can’t give it to patients in extreme pain.

They don’t carry it for fear of the situation (that I found myself in).”

After the collapse of his trial at Teesside Crown Court, when he declined to give evidence, Dr Martin was struck off by the General Medical Council (GMC) for a “deliberate course of conduct”

that hastened the death of 18 of his elderly patients.

Dr Martin, now of Penmaenmawr, in Wales, was branded “reckless” and “arrogant”

by the GMC. He later told the Telegraph newspaper he had “helped people die” and felt no guilt or remorse.

He said that in 20 years’ time his actions would be the accepted practice. However, he added that the establishment was preventing debate on the issue of euthanasia because it was dictatorial.

He said he no longer wanted to take part in the discussion, but welcomed the fact others are now leading the debate.

“I just want a quiet life now.

I’ve had my say and I’ve been put in the public eye for the past five years. I don’t want to be in any more trouble.”

Dr Martin said he was still getting over the shock of seeing the front page of a tabloid newspaper with a picture of his face accompanied by the words “Doctor Death”.

He added: “I don’t feel disgraced and I don’t feel I did anything wrong.

“I’ve been back [to Newton Aycliffe] and I have had people put their arm around me and say what a good doctor I was – I’ve had fantastic support.”

Last night, Paul Gittins, the son of Harry Gittins, said euthanasia was helping someone to die who was suffering – after being given their permission.

He said: “Dr Martin just killed people, but I do agree we need to have a debate about it, if only to stop misguided people like him from taking the law into their own hands.”

Mr Gittins said he would take advice on whether civil action was possible.

Allison Moss, the daughter of Frank Moss, said she had feared the second trial might not go ahead.

“What is he trying to do now?” she said. “Is he just trying to hurt us even more? He probably doesn’t think about it, but that’s how I feel.”

Others have called Dr Martin an “angel of mercy”.

Albert Cubitt, 88, said his wife Bessie, who died in January 2001 after battling lung cancer, was “grateful” for Dr Martin’s intervention.