This week one the UK’s leading experts on drugs policy, Prof Alex Stevens, resigned from the government’s Advisory Council on the Misuse of Drugs (ACMD). His resignation came almost 10 years to the day since I was sacked as the council’s chair.

My “mistake” 10 years ago was to argue that UK drug policy was politically rather than scientifically based. It seems that nothing has changed in the past decade: evidence still takes second place to politics with regard to drug policy decisions. Stevens resigned because the Home Office – the government department in which the ACMD is based – refused to allow the appointment of at least two other experts selected to join the council. It appears their appointments were blocked after political vetting by the Home Office, which discovered some previously declared criticisms of government policies.

One of those blocked is a world expert on drug laws. It seems the justification was her being critical of government

We know one of those blocked to be Niamh Eastwood, the executive director of the charity Release. She is a world expert on drug laws and their impact on individuals and society. As well as being at the forefront of thinking about drug laws, Release has a major educational role in training aspiring drug policy experts from disadvantaged countries around the world. Eastwood is therefore highly suited to the role of a UK drug policy government adviser.

It seems that the justification for blocking her was two Twitter posts critical of government. One accurately, if rather colloquially, challenged a statement made by the then drugs minister, Victoria Atkins, that there was no evidence that safe injecting rooms worked. In fact, there is 30 years worth of international research evidence that they do work. For the drugs minister not to be aware of this evidence either reflects an absurd level of ignorance or a wilful resistance to acknowledge it.

The second tweet related to Windrush, where Eastwood simply expressed the opinion, which most reasonable people share, that the scandal was an outrageous miscarriage of justice. Even the then home secretary, Sajid Javid, made the same point. These two tweets were taken as evidence that she did not meet the standards required to join the ACMD. It is believed the current chair of the council protested about her being debarred and asked for a review of the case. This review has just concluded and supports the Home Office decision – a finding that prompted Stevens to resign in protest.

When I was sacked in 2009 the Labour government of the time worked with Fiona Fox, head of the Science Media Centre, to review the rules relating to the government’s scientific experts. The guidance concluded that experts should not be dismissed for publicly expressing opinions differing from current government policy. It is time for this principle to be extended to would-be members of expert committees. There are a number of legitimate reasons to turn down a person’s application to join an expert committee. Disagreeing with the government of the day should not be one of them.

To the average citizen it might seem hypocritical that Michael Gove, a self-confessed drugs lawbreaker, sits as one of the most senior cabinet ministers, while a world-renowned expert is denied the opportunity to help develop better drugs policies because she tweeted uncontroversial observations about breaches of trust and competence in government. If ever there was an example of self-serving behaviour by the political elite, this is it.

It is also shortsighted. Drugs research has made great gains since I was dismissed a decade ago. The Home Office, however, has stood still, fighting yesterday’s drugs battles and failing to understand how the world is changing around it. Advances are being made in the fields of medical cannabis and psychedelic research, that have the potential to treat individuals with conditions such as multiple sclerosis and severe depression. With deaths from illegal drugs on the rise, there is also a pressing public health need to pursue policies that reduce harm, rather than promote criminalisation.

The government needs the best possible expert advice to develop effective policies. It needs a strong advisory council with a diverse membership, free from the taint of political interference. Beyond this, it seems to me that it is also time for the UK to act as most other democracies have done and place decision-making on drugs policy in the Department of Health.

By doing so, government policy would have a better chance of being informed by an understanding of evidence. And policy decisions would not be so contaminated by the Home Office, whose blinkered view of drug use as primarily a criminal problem, requiring the criminalisation of drug users, is a tool to court populist authoritarian notions of criminal justice in the electorate. The severe harm this approach causes cannot be overlooked.

• David Nutt is professor of neuropsychopharmacology at Imperial College London. He was chair of the UK’s advisory committee on the misuse of drugs until 2009