David Blunkett, the Home Secretary, admitted yesterday that the prison population was "rocketing" as he joined the Lord Chief Justice in calling on magistrates and judges to use community sentences more.
The unprecedented comments revealed Mr Blunkett's concern at the record number of 70,000 prisoners being held in the overcrowded jails of England and Wales.
Home secretaries usually avoid making comments that could be interpreted as interfering with the independence of judges and magistrates. But Mr Blunkett voiced his concerns that people were being inappropriately jailed after Lord Woolf, the Lord Chief Justice, issued his own warning to sentencers yesterday.
Lord Woolf called for an end to unnecessary custodial punishments as he, in effect, released a jailed fraudster by drastically reducing his sentence in the Court of Appeal.
Sitting with two other senior appeal judges, Lord Justices Rose and Judge, the Lord Chief Justice warned of the "corrosive effects" of prison overcrowding on the criminal justice system. He said: "We trust all courts will heed the message which the court is giving today. That message is: imprisonment only when necessary and for no longer than necessary."
Lord Woolf was giving the court's decision in the case of a former building society cashier jailed for 12 months for stealing £11,120 from accounts. The judges reduced to four months the sentence passed on Mark Kefford, 26, of Southampton, in November, allowing his immediate release.
The Lord Chief Justice said courts should not be deterred from jailing those guilty of violence, intimidation or other grave crimes, particularly against vulnerable people.
But he said that in cases of "economic crime", such as obtaining credit by fraud, a community punishment or a fine could be more appropriate. For a person with no criminal record, just having to appear before a court could be a significant punishment, he said.
"It is preferable that the Prison Service is in a position to deal effectively, uninhibited by the corrosive effects of overcrowding, with those cases for whom imprisonment is necessary," he said.
With the jail population standing yesterday at 69,969 and threatening the system's capacity of 70,834, Mr Blunkett promptly backed Lord Woolf.
"Overall crime is falling but the prison population is rocketing," hesaid. "Increasing numbers of people are committed to custody for less than six months. This displaces existing longer-term prisoners to jails around the country. Their programmes of training, adult literacy and preparation for work on release are completely disrupted."
He said such sentences "overloaded" prisons and did little to rehabilitate prisoners. "If offenders lose their job or their homes and their relationships break down they are no better equipped for a law-abiding life ... it is not surprising that reoffending rates are high."
¿ Yesterday's warnings came as Nacro, the charity for ex-offenders, revealed figures showing that England and Wales now equal Portugal as Europe's biggest jailers. The rate of imprisonment is now 131 per 100,000 population, compared with a European Union average of 97 per 100,000.