Ministers urged to look at jail sentences

In a joint report, the chief inspectors of prisons and probation said the penal system could not handle the "huge" numbers of inmates given such sentences.

Critics accused Ministers of presiding over chaos and trapping prisoners in a "maze with no exit".

The report said the probation system lacked the resources to deal with the thousands of prisoners on Indeterminate Sentences for Public Protection, who now make up one in 15 of the total prison population.

Indeterminate sentences were introduced in 2005 for the most dangerous offenders.

In theory they would not be released until they had completed courses aimed at reforming them and proved they were safe to be back in society.

But the terms were used on such a scale they "flooded" the prisons system and two years ago they were drastically scaled back.

Barely one per cent of such prisoners have been released.

By the end of last year, 5,788 adults had been given indeterminate sentences, and half of those had served more than the recommended tariff.

Only 75 of such prisoners had been released from custody and managed to stay out.

Two offenders won a court victory in 2008 after complaining they had not had the opportunity to prove they were rehabilitated because of a lack of courses.

Chief Inspector of Probation Andrew Bridges said today: "We consider that the present position is unsustainable. This suggests the need for a major policy review at Ministerial level."

Juliet Lyon, director of the Prison Reform Trust, said the review offered further evidence of the chaos caused by the ill-thought-out sentence. "The Government's response has veered between bravado and blankness."