The Advisory Council on the Misuse of Drugs, a respected body of drugs counsellors, doctors, police and judges, argues that cannabis should remain a Class C drug – even though it is a "significant public health issue".

What is the point in assembling such an experienced commission, which has conducted a major report listing no fewer than 21 recommendations to cut the use of cannabis, and then ignoring what the majority have to say about the most crucial element, the classification?

It continues a dangerous trajectory. By asking the Home Secretary to reclassify cannabis as a Class B drug, the Prime Minister is arrogantly riding roughshod over official advice, using a massive great sledgehammer to crack a nut, and displaying a chronic lack of understanding about the reality of a major issue in modern Britain.

And you might ask, why do it? Especially now. Brown has been accused of "following the tabloid agenda", but this is hardly a vote-catcher. Cannabis use has actually declined by up to 25 per cent in the past five years.

The most recent statistics from the British Crime Survey show that 2.6 million adults in England and Wales used cannabis in 2006/7, a fraction of the 52 million-plus population.

Reclassifying the drug won't prevent individuals from wanting to smoke it. In fact, many, especially the young, won't even grasp the legal implications. As Deborah Cameron, from the drugs and alcohol addiction treatment charity Addaction, says: "The young people that we see don't think about the classification of cannabis before they smoke weed. They don't understand the system and it doesn't deter them."

But, no doubt, they would soon understand the prison system if they were to find themselves banged up for five years, the maximum sentence for possession of a Class B drug. It beggars belief that the Government is planning to send even more prisoners into our already-overcrowded jails.

And, in doing so, they are inculcating more individuals into the cycle of offending and imprisonment which characterises so many lost lives – lives which often end up turning to ever-harder drugs to escape reality.

Some senior police officers have called for a policy of "discretion" to be applied to punishment for cannabis possession in order to avoid criminalising young people who are experimenting.

It would ensure that regular users are tackled. Repeat offenders would be dealt with severely, a policy that is difficult to implement at present because records are not kept of those caught with cannabis and let off with a warning.

You might think that Home Secretary Jacqui Smith would be the first to appreciate this kind of intuitive approach: she has admitted to trying the drug as a student at Oxford in the 1980s. Surely, as the ACMD argues, it makes more sense to target the dealers who plague schools and colleges than haul up every daft teenager who is caught with a tentative spliff.

And, crucially, as the ACMD says, it is imperative to introduce draconian measures to punish the "skunk farmers" who proliferate across our region and produce the highly-potent variant of cannabis, thought to be especially deleterious to mental health.

Skunk farmers like to buy up terraced houses – easy to heat, you see – solely for the purpose of growing cannabis plants. In one raid in Sheffield last year, police found 34 kilos of cannabis plants, worth about £68,000 – probably more than the value of a skunk house in the current market.

If Gordon Brown and Ms Smith want to get tough, then this is where they should start. I'd wager that almost every town and city in Britain has a seedy network of organised crime that is dealing, growing and profiting from drugs.

Stamp all over them, and at the same time, use the ACMD report as a springboard to pump funding and resources into devising a coherent long-term strategy to get that "tough message" across.

I know plenty of drugs casualties who I can invite round to teach my children about the error of addiction. But I'd like to see every parent given the information to discuss drugs honestly with their families so that they don't resort to moral panic unlike our Prime Minister.

Preventative work in schools should be prioritised. And Ministers need to accept that cannabis is as common a drug as tobacco and alcohol in some communities and, as the ACMD report recommends, treatment programmes should be combined for maximum impact.

This requires deep and ongoing engagement with drugs professionals. Knowing what we know about communication problems within the Brown administration, the possibility of such an approach being established – and bearing useful fruit – seems remote.

A friend, a drugs policy worker, recalls being asked to Number 10
for a pow-wow with Tony Blair, who had assembled a informal gathering of experts to sound out their views.

"Imagine that happening today and making the slightest bit of difference," he says. Neither of us can. It is clear Gordon Brown intends going his own way without listening to anyone else – the one lesson he claims that he had learned from last week's disastrous election results.