In his first speech on penal policy, Lord Phillips of Worth Matravers, the Lord Chief Justice, said that most offenders who serve short prison terms would re-offend within two years.

The aim with such offenders, who are anti-social and a "costly menace to society", should be rehabilitation, he said — and that could best be achieved in the community.

Lord Phillips, addressing the Centre for Criminology at Oxford University, also hit out at the "serious misconception" among a majority of the public that judges were soft on criminals. The reality was that the public was unaware of the "relative severity of the sentencing regime in this country."

In 1940 the prison population was 10,000; today it was approaching 80,000, he said.

In the last 20 years there has also been a "marked increase in the length of the average sentence imposed for the more serious offences, drug offences, criminal damage, violence and burglary. And most of that increase has been in the last ten years." Prisoners serving four or more years had doubled in number over the decade.

What was more significant, he added, was that there had also been a big rise — 31 per cent — in the proportion of offenders sentenced to less than 12 months. In 1994 this totalled 38,719 but by 2004 it had risen to 61,669. Most — 87 per cent — were jailed for six months or less, partly reflecting the limit on magistrates’ powers. However, this is set to double in November.

Most of the offenders were not "serious professional criminals," Lord Phillips said. But "within two years of release, the majority have been re-convicted."

"This fact is proof of their inadequacy, for the able offender is not all that easily caught and convicted. They are nonetheless an anti-social and costly menace to society. It is my belief that, when sentencing this category of offender, the primary objective must be rehabilitation."

For serious offenders, rehabilitation could take place in prison, he said. But for others it could more effectively be achieved as part of a community sentence, although it was essential that this was perceived by all to be "real punishment" and "tough, punitive sentences."

Lord Phillips went on to make a strong case for community penalties, adding that the message must be got across that they were "not a soft option."

Such penalties have involved up to 300 hours of community work, such as cleaning graffiti from buildings, restoring childrens' playgrounds or restoring Brunel’s ship, SS Great Britain, in Bristol.

"Provided the resources are allocated, I would contend that a community sentence is more likely to prevent re-offending than a prison sentence," he said.

Short prison sentences had not to date been accompanied by rehabilitation, either during the sentence or after release. "Such sentences punish and punishment is important but they do not tackle the underlying causes of the offending behaviour," he said. By contrast, community penalities meant an offender was more likely to keep his home or job, if lucky enough to have either. The rate of re-offeding had been shown to be 53 per cent compared with 68 per cent; and they were less expensive.

"It costs more to keep a young man in prisons than it would cost to send him to Eton."

Explore Law

• Columnists

• Law Panel

• Law Reports

• Student Law

Times Recommends

• BGC 'set aside £40m to lure Tullett brokers'
• Legal aid review to ensure value
• Fears as 21 magistrates' courts face closure