HUNDREDS of prisoners in British jails are to be freed over the next few weeks after a sentencing blunder which could cost the taxpayer millions of pounds in compensation.
Sources estimated that up to 4,000 inmates will see their sentences reduced, and between 400 and 500 are set for imminent release following years of miscalculations by the prison service.
Some 33 inmates were let out of Haverigg prison in Cumbria on Wednesday night - the start of a series of releases across England and Wales. Those serving life sentences are not affected.
Probation officers warned last night that the public could be put at risk because staff had not been given adequate warning of the releases.
Opposition politicians seized on the sentence slip up to heap fresh embarrassment on the Home Secretary, Mr Michael Howard, just as he is trying to spearhead a fresh law and order drive for the Tories.
The reductions in sentences appear to follow almost 30 years of miscalculations by the prison service dating back to the 1967 Criminal Justice Act.
Inmates who have served time in jail on remand before their trial have this period knocked off their final sentence. But in cases where prisoners had been ordered to serve several sentences consecutively, the period spent on remand had been taken into account only once.
So, for example, an inmate who had served six months on remand and was given three sentences consecutively had only six months cut off the time he spent behind bars, when it should have been 18 months.
New guidance on sentences was sent to prisons earlier this month, following several court cases in which inmates had challenged the prison service interpretation of the law.
According to one estimate, prisoners can claim £95 for each extra night spent behind bars.
George Howarth, the Labour spokesman on prisons, said: "The consequences for the public finances will be quite appalling. The already overstretched taxpayer will have to foot the bill for the government's incompetence.
A lawyer, Mr Adrian Clarke said claims could cost "up to £10 000 per month for each prisoner affected.