Charging prisoners two-fifths of their earnings to help support victims is forcing some inmates to give up work designed to help cut reoffending, inspectors said today.

The counter-productive policy is stopping prisoners taking jobs which could help them to carry on working and turn away from crime on their release, chief inspector of prisons Nick Hardwick warned.

The critical report on Standford Hill open jail in Kent also found inmates rated the food among the worst of any prison in England and Wales, with uncooked meat being served while still frozen.

Inspectors said some prisoners were being forced to give up jobs that could have helped them settle back into the community after their release because the victims’ surcharge was so high that they could not afford the travel costs.

Prison governors should be given greater discretion over whether to take a prisoner’s travel costs into account when calculating their net earnings from which the levy would be deducted, Mr Hardwick said.

Under the Prisoners’ Earnings Act, 40% of a prisoner’s net earnings over £20 a week from external jobs are deducted as a levy towards Victim Support, with governors able to use their discretion only in “very exceptional circumstances”.

The report on last December’s inspection said: “The Prisoners’ Earnings Act was beginning to have an adverse effect on prisoners finding employment outside the prison by making it uneconomical to take work which incurred substantial travel costs.

“More than one prisoner was finding that after necessary expenses, such as travel, they were significantly out of pocket.

“This was beginning to limit the realistic scope for prisoners to find jobs (near enough to their home) which could provide continuity of employment after release.”

Juliet Lyon, director of the Prison Reform Trust, said: “Ways for offenders to make amends to victims do not have to come at the expense of vital opportunities for rehabilitation and resettlement.

“It is clearly counterproductive if the levy deducted from prisoners’ earnings means that people in prison can no longer afford to travel to work and so reduce the risk of their reoffending.

“Prison governors should use the discretion given them in the use of the levy to assist offenders in helping them to lead a law-abiding life on release.”

The report, which found significant improvements were needed, also warned that the inmates were being given food that was not fit for consumption.

Meals for more than 460 prisoners are brought in to the jail in heated trolleys in the back of a van each day from nearby Elmley prison.

But there is no record of any temperature control once the food has been put on to the vans.

The inspectors said: “Prisoners told us about, and we witnessed, some food being served lukewarm, and some meat products we observed were still frozen at the point of service.

“Chips were cooked onsite in the serveries but this was often done around two hours before service, so that the quality had deteriorated by the time they were served.”

Mr Hardwick added: “Nine out of 10 men were dissatisfied with the food – among the worst responses we have seen – and they were right to be so.

“Some food that was served was not fit for consumption.

“Until relatively recently, Standford Hill appears to have been coasting. Outcomes are reasonable in most areas but the prison is exposed by some significant areas of concern.”

Michael Spurr, chief executive of the National Offender Management Service (Noms), said: “Standford Hill has made some good progress despite a transition period to a new management structure.

“I am pleased the chief inspector found that the prison has made progress in the areas of concern and I am confident that the new team will drive forward further improvements.”

A Prison Service spokeswoman said: “Since the inspection, measures have been put in place to support prisoners working on day release with travel costs.”

The meat is understood to have been a pork pie which was meant to be served cold but had not been given enough time to defrost.