Leading article: An injection of common sense

Britain's hopelessly overcrowded prisons cry out for reform; or rather, a legal system that incarcerates too many people who are not violent and pose no obvious danger to the public.

But cutting prison numbers – now 82,000 and rising – is like cutting public spending. No one seems to know precisely where to start. Which is why the Government would do well to look closely at the findings of the latest report by the UK Drug Policy Commission.

The think tank recommends greatly reducing the number of minor criminals who are given custodial sentences and giving them community sentences instead. The logic behind these findings is firm; this isn't liberal hand-wringing. The plain, though distressing, fact about our prisons is that they have become schools for drug addiction. Heroin and other class A drugs are increasingly rampant among prisoners, so that jailed class A drug users are unlikely to wean themselves off their addiction while serving jail sentences.

It is true the Government has invested significant resources in drug treatment programmes in prisons. But the effect of these programmes, as the report points out, has yet to be measured scientifically. Moreover, the programmes operate only within prisons; there is no connection between the programmes and the follow-up care available to addicts returning to the community. Some fall between two stools, hence the disturbing number of heroin addicts who die from overdoses within only a fortnight of release.

No one is suggesting that violent addicts should not continue to be incarcerated as a protective measure. The question is what to do with the non-violent majority among the 125,000 estimated problem drug users, most of whom fund their habit through petty robbery, the handling of stolen goods, fraud and street begging. The commission believes community sentences could be part of the answer for many of these less problematic offenders whose condition merely worsens in prison. The challenge for the Government is to spell this out, instead of cravenly playing along with the public's ill-defined but undoubted thirst for tougher, longer, sentences in general.

What the average member of the public really resents, however, is muddle and inconsistency in sentencing and the idea that criminals are being ''let off'' for no good reason. But if the Government explained that routine sentencing of addicts to custodial terms did more harm than good – that custodial sentences are horrendously expensive and overcrowded jails are breeding grounds for more crime – there is a decent chance people would swallow a change of direction. Since it is clear the current policy is not working, it is worth a try.