Prison officers and Labour MPs criticised the privatisation plans, but a process is now under way to identify the worst of the 21 and open them for market testing.
Brian Caton, national vice- chairman of the Prison Officers' Association, warned that his union would rule out no options in its opposition to the plans, even though a court ruled last year that it was unlawful for prison officers to take industrial action.
He said: 'The POA will respond with every available effort that it has got to protect the best interests of its members. We are convinced that the inevitable outcome of what is being put into place is redundancies.' The Prison Service said it had earmarked 12 out of the 133 prisons in England and Wales against key performance indicators, such as cost per inmate, escapes, assaults, prisoner activity and time unlocked. Nine open prisons have also been put under scrutiny.
Between now and September, governors and staff will be able to defend their prisons and argue why they should not be privatised. The two least able to justify their existence will be put on the market and private security companies will be invited to bid against staff for contracts to run them.
The Prison Governors' Association criticised the plan, arguing that it would create uncertainty among officers and governors. David Roddan, general secretary, said: 'Twenty-one governors and their staff have been plunged into a period of anxiety due to a policy that has everything to do with party politics and nothing to do with any criminal justice issue or real value for money.'
The prisons named are: Aylesbury, Feltham, Reading, Coldingley, Hollesley Bay, Rochester, Erlestoke, Huntercombe, Shepton Mallet, Everthorpe, Northallerton and Styal. The open prisons are: Ford, Morton Hall, Sudbury/Foston, Hewell Grange, North Sea Camp, Kirkham, Spring Hill, Leyhill and Standford Hill.
Four private prisons have already been contracted out - the Wolds, Blakenhurst, Doncaster and Buckley Hall - and private firms will be invited to bid to design, build and manage six new prisons.
Alun Michael, Labour's home affairs spokesman, said: 'This is basically a cost-cutting exercise which, on past experience, is likely to end up costing the public more and putting the public and prison officers in danger.'Reuse content