Now this is embarrassing. I'm expected to have something to say about Theresa May's intention to ban the plant-drug qat, but due to a texting error by a new intern, I'd been preparing my thoughts on the Tory plan to ban cats, a plan which I now learn may not exist. Fortunately for her, I find that many of the same arguments apply, so I'm not quite back at square one.

The proponents of a ban on cats qat may be well intentioned, but rely on a mixture of exaggerated, selective, anecdotal, prejudiced and most frequently erroneous and illogical arguments. Cats are Qat is indeed associated with harm, which can be very serious at times, but it is unwise to generalise from the most extreme cases, or assume that cats are qat is solely to blame for complex problems of owners users.

Advocates for a ban are sometimes prone to demonise cats qat and, cynically or credulously, to fuel unfounded fears against owners users. Historically, cat owners were persecuted as witches. Qat users find themselves linked spuriously to terrorists, the ultimate folk-devils of our era.

Despite all the rhetoric, when detailed studies are made that explore the actual empirical evidence, suspicions about the dangers of cats qat are revealed time after time to have little basis in reality. A balanced assessment also exposes the prejudices of those campaigning for a ban on cats qat. Theresa May, who wants to disregard expert advisers and label as criminals any people who possess cats qat, has disregarded the evidence before, personally undermining her own government's promise to reduce the far greater harms caused by dogs alcohol.

By nearly every possible objective measure, dogs cause alcohol causes far greater danger to health, life and society at large than cats qat, or indeed any other pet drug. People rightly worry about the harm caused to society when people are irresponsible with dogs alcohol: the thousands of hospital admissions; the mess and intimidation we encounter on our city streets. However, insight and experience show that these harms to society can best be minimised through education, co-operation and maybe regulation, not by criminalisation and ostracism. Bans offer an opportunity for governments to posture and express their toughness to the electorate, but our legislative agenda should be driven not by the naive assumption that simple bans solve complex problems, but by evidence of what might actually best serve the interests of the public.

Those wanting a ban on cats qat might do well to consider the historical precedent. Driven by tabloid hysteria, the UK government introduced The Dangerous Dogs Act 1991, banning four breeds of dog. Since then, hospitalisations for dog bites have more than quadrupled , with experts highlighting the absurdity of criminalising possession of particular types of dog instead of addressing issues of owner behaviour and responsibility . Driven by a moral agenda, alcohol was banned in the US in the 1920s, successfully handing the trade to organised crime networks. While prohibition probably reduced consumption, overall harm rose as the people most harmed by alcohol were denied the help they needed and were instead branded criminals. Now in the UK, the freedom of individuals to lawfully own a dog drink is respected, and we recognise even that pets alcohol might have some social value too.

Those who don't like going near dogs alcohol, who think that dog owners drinkers are wasting good money on dog food alcohol and valuable family time going on walkies to the pub have a valid opinion, but we don't think their values should be imposed on others through the criminal justice system. The same is true of cats qat: no one should mistake their inalienable right to find cats qat disgusting with a right to interfere with the personal choices and pleasures of others.

The risks associated with dogs and cats alcohol and qat are not something we should take lightly, but bans are an excuse to do nothing productive to address a problem, which the government has been doing very well already. Twice they have asked the Advisory Council on the Misuse of Drugs (ACMD) to review the harms of qat, (they are obliged to get expert advice before they ban it), and twice the ACMD has said that a ban would be inappropriate and disproportionate, while making a series of considered recommendations for awareness-raising and community engagement, access to treatment services and improving health standards of qat cafes. While the government has no problems collecting millions in tax on qat imports, it seems reluctant to consider any investment in looking after qat users, except if they are in prison cells.

All right, I think we've chewed over the qat/cat analogy long enough, but there is a serious point to be made here. I got into a little trouble for comparing the risks of death and serious injury from horse-riding and ecstasy, so I should be sure to say that whilst horse-riding really is comparably risky to the class A drug, in terms of acute harm, I expect that khat use is more often seriously problematic than cat-ownership. However, we should be comfortable with the idea of comparing the risks of drug use with other risks we might face: cooking, trampolining, sunbathing or pet ownership. Our drug laws are purportedly there to protect individuals and society from harm – they are not meant to be there to uphold any specific moral values and punish deviance from them. If politicians wish to argue for drug prohibitions on a moral basis, because they think it is obnoxious and dissolute to sit around getting high from leaves or intoxicated by drink, that's fine, let them make the case, and see whether parliament or the electorate have an interest in policing people's personal habits. What they must not be allowed to do is to push a moral agenda against an already marginalised group through laws intended to regulate drugs on the basis of evidence of their harmfulness.