A year ago, Mike Barton was surprised that he was being described as the "former" Chief Constable of Durham. He had not left the post. He had just penned an article denouncing the War on Drugs for The Observer. “They just automatically assumed that nobody would say that much and say it when they were in power.”

For years there has been a depressing trend in UK drugs policy. Politicians and police officers who have retired are not shy to point out that the War on Drugs has been self-defeating. But those in power are rather more reticent to do so. “Well why didn’t they say something when they were in the arena?” Barton asks. He bucked the trend when, last September, he wrote: “ending the war on drugs will cut crime.”

Immediately he became a hero for all those calling for a rethink of UK drug laws. But Barton is very different to most. He is no hipster but a hard-nosed policeman with over three decades’ experience.

“I’ve thrown the kitchen sink at dealers,” he explains. In his role as Chief Constable of Durham, Barton has developed a system called Operation Nimrod to clamp down on drug dealers. “We’ve got undercover cops every day buying drugs from drug dealers and then turning those operations around very quickly and arresting drug dealers,” he says. “But we’re not stemming the tide.” He recounts the futility of one particularly onerous operation. “That job had taken six months, cost us over half a million quid, and we locked up 34 people. And within between two and four hours, the drug supply was turned back on.”

For much of Barton’s career fighting drugs he did not stop to consider whether police orthodoxy was wrong. It was while he was working in Blackpool in the 1990s that began to change. “I would regularly go to people who’d die from drugs overdoses,” he explains, growing more exasperated. He remembers a young man in his early 20s, who had just been released from prison where he was taking heroin far weaker than that available on the streets. After he was released he overdosed and died. “The reason why people who take heroin are unhealthy is because we allow that as a society. We force people who take those sorts of drugs, are addicted to those drugs, to buy it from some people, desperately bad people.”

Barton believes that the current policy is letting addicts down, with disastrous consequences. “I get dreadfully upset when addicts come forward for treatment and they are still in the thrall of organised crime by having to go to them for the heroin to which they have an addiction,” he says. “We’ve got tens of thousands of people in this country who have hepatitis and HIV as a result of drug addiction. But because we forced them to buy their drugs to which they are addicted from organised criminals, those people have nothing, are left just to squat.”

As for those who say that the NHS should not be in the business of giving drugs to addicts, Barton says the alternative is both more damaging for addicts and much more expensive. “What we then do is we pay for their retrovirals when they become HIV positive or when they get hepatitis. It costs about £80,000 a year to give people retrovirals,” he says. He supports giving heroin in controlled doses to those recovering from heroin addiction, rather than methadone, as is currently done – leading to huge numbers of addicts continuing to purchase heroin, resulting in a concoction of the drugs that is even more dangerous. “Why don’t we give them heroin then they don’t go and top up? What we should do is we should challenge their addiction. I’m not saying that they’re on heroin for the rest of their lives, far from it.”

For much of his career Barton has been in despair about the sheer stubbornness of those in power about drugs. While the current government has trumpeted its emphasis on “evidence-based policy” it has refused to countenance a fundamental shift in drugs policy – despite a Home Office report in October finding no link between the severity of drug laws and levels of drug use between different countries. Still, the very fact the report was commissioned, and that the Commons Backbench Business Committee recently granted a debate on drug policy – even if it was non-binding and had a lamentable attendance from MPs - hints at the fragmentation of the consensus on the War on Drugs.

Barton is optimistic that could be the case. He believes that, as the issue gains more prominence, “public opinion will sway more, and I think there will be a significant majority of people who say, ‘Let’s try something different’.”

He also spies a change in tack from some decision-makers, saying that there are “increasing numbers of colleagues who want to open the debate.” Austerity has made the case more pressing: police forces who are cutting crime in spite of cuts cannot justify the grossly inefficient use of resources that clamping down on drugs entails. “My example of those two addicts - to strangle supply for a matter of hours, cost us half a million quid,” he says. “I would much prefer to deploy my resources to protect more people, such as people who are potentially at risk of child sexual exploitation, or protecting people from crime on the internet.”

While David Cameron is an ardent supporter of the War on Drugs, Barton has been encouraged by aspects of current government policy. “The coalition government’s policy of focusing very much on recovery, is to be applauded, and I’ve seen the benefit of that locally.” He credits the greater emphasis on recovery with leading to a drop in UK drug use, but cautions against this vindicating the underlying approach on drugs, which has remained the same since the 1971 Misuse of Drugs Act. He notes that Portugal which has been “less risk-averse” in its drugs policy has “seen much more significant improvements than we have.” Since Portugal decriminalised the possession of drugs in 2001, the number of drug-related deaths has fallen from 80 to 16. 2,955 drug-related deaths were registered in the UK in 2013 – 20 times as many per head of the population as in Portugal.

Barton thinks that the greatest beneficiaries of a change in UK drug policy would not be here but in the countries ravaged by the War on Drugs. “The Class A drugs trade, the black market that’s been created, is threatening our civilization,” he says. “My fear for the world is that increasingly there are more failed states on the back of Class A drugs trafficking.” He notes that, as tough as his own job can seen, in Mexico “the average life of a chief is about a year.” Indeed, it is the desperate situation in Mexico that is making the debate on drugs so urgent in the United States. “America can’t protect its border with Mexico, and what they’re recognising is if Mexico becomes a failed state that threatens America. And I think that’s one of the reasons why they’re in more of an open debate in America than there ever has been before.”

Britain continues to lag America in confronting the effects of the War on Drugs. That Barton feels his position has been misrepresented – “People just dismiss me, say ‘Oh yes, he just wants people all on drugs.’ Well I don’t” – is proof of this. He pleas “for open, adult debate around this, rather than simply being shouted at and forced to say ‘you’re bad, you’re wrong’.” Thousands of people whose lives are decimated by drugs in the UK – and many times more that in Latin America – will hope that those in power head Barton’s wish for a sober, evidence-led drugs policy.