The reclassification of cannabis from a class C to a class B drug has finally come into effect. The government defied expert scientific and medical opinion, which opposed reclassification on the grounds that cannabis is not as harmful as other class B drugs and that its harm was not sufficient to warrant harsher penalties. The government's own Advisory Council of the Misuse of Drugs recommended that it should remain a class C drug.

Ignoring the expert evidence, the home secretary, Jacqui Smith, caved in to irrational, ill-informed anti-cannabis hysteria. Making no distinction between responsible, occasional use and reckless, constant abuse, she has now reclassified all cannabis enjoyment as dangerous and harmful, and upped the maximum penalties for possession from two to five years.

This signals to the police and the courts that they should treat cannabis more harshly, on a par with demonstrably damaging banned narcotics. Meanwhile, the most socially harmful drugs, alcohol and tobacco, remain legal and outside the scope of anti-drugs legislation.

This selective get-tough-on-drugs policy seems motivated by the government's cynical desire to win few extra votes from Daily Mail readers. It has little to do with any genuine or effective attempt to encourage less frequent and safer cannabis use via advice such as: "Eat it, don't smoke it" and "Every day? Perhaps not good. Save it for a special occasion."

Millions of Britons enjoy cannabis sensibly, in moderation and without harm to themselves or others. Tens of thousands use it to ameliorate the symptoms of diseases such as cancer, HIV and multiple sclerosis.

East Londoner Edwin Stratton is one of them. For the last 18 months he's been using cannabis to treat his disabling coeliac condition. He's found it immensely effective, reducing his pain and nausea and improving his appetite. It has enabled him to cut his prescription medicines by half, saving the NHS a lot of money in the process.

Experiencing the medical benefits of cannabis and being of modest financial means, Stratton decided to grow his own. Self-production not only cut his costs, it also eliminated the need for him to deal with the criminal gangs who supply cannabis; striking a personal blow against the organised crime syndicates that dominate the drugs trade. Also important, home growing enabled him to protect himself from the pesticides and other chemicals frequently used by cannabis cartel producers.

Unfortunately, in May 2008, the police discovered Stratton's home-grown during a routine investigation. He acknowledged that he privately grew cannabis plants in his home, to combat his medical condition. Rejecting a police caution, he chose to fight the case. He believes that under the Human Rights Act the denial of his right to grow and possess cannabis is an invasion of privacy and a denial of property rights. It is also discriminatory in that this right is not denied to people who choose to brew at home the equally or more harmful drug, alcohol.

Stratton was duly charged with production of a controlled drug (then class C), in contravention of section 4(1) of the Misuse of Drugs Act 1971.

Stratton attended Waltham Forest magistrate's court in October 2008, accompanied by Darryl Bickler of the Drug Equality Alliance, acting as his "McKenzie Friend". He declined to plead, and instead moved to quash the indictment as an abuse of process. The magistrate agreed to a stay of proceedings, giving Stratton leave to apply to the high court for permission for a judicial review of the decision to prosecute him. His judicial review application is eloquent and compelling.

Stratton is backed by the Drug Equality Alliance with the support of the drug charities Release and Transform Drug Policy Foundation. The essence of his legal defence includes four issues: the right to privacy, the protection of property rights, the unequal application of the law to controlled and non-controlled drug users and the maladministration of the Misuse of Drugs Act – most notably the government's failure to make drug use penalties uniformly commensurate with the harm they cause.

According to Stratton:

I am not fighting the law as it stands, but its misapplication by the government and its state agencies. The Misuse of Drugs Act 1971 is a pretty good piece of legislation, because it's designed to evolve along evidential lines. It explicitly provides for the relaxation of controls on drugs in accordance with scientific evidence of relative harms. However, government and judicial policy hasn't developed in line with scientific evidence, and vast swaths of the act have clearly been ignored or not understood.

Stratton was recently referred to a Whipps Cross hospital pain specialist. After mentioning the relief cannabis provides him, the doctor offered to prescribe something similar. He issued a prescription for Nabilone, a synthetic analogue of Delta-9 THC, which is virtually identical to the main psychoactive substance in cannabis. It is ironic that the government forbids Stratton to use natural cannabis, but allows the NHS to prescribe him a synthetic version.

Unfortunately, Nabilone does not work for Stratton. Moreover, if it did work, it would cost the NHS and the taxpayer approximately £9,000 a year. Stratton, in contrast, can grow a year's supply of more effective herbal cannabis for less than £250 – a payment he is prepared to cover himself. Any rational cost-benefit analysis would conclude that Nabilone is medically inferior and a financial rip-off of the NHS.

Whichever way you look at it, the government's drug policy is a mess: unfair, inconsistent, costly and ineffective. Good luck to Edwin Stratton in his efforts to secure a rational, evidence-based, uniform, workable and humane policy that applies to all controlled and non-controlled drugs, without prejudice or discrimination.