Sentencing reforms introduced by the Government have put a strain on jail resources and added to the problem of overcrowding, prison governors are warning.
At the heart of their concerns are new "indeterminate" sentences for dangerous offenders, of which 2,000 have been handed out since their introduction in 2005.
The Prison Governors Association (PGA) will lodge a formal protest when it gives evidence to the all-party House of Commons Home Affairs Committee, which last week announced an inquiry into sentencing.
The intervention will embarrass the Home Office because the PGA's 1,200 members are senior officials responsible for running Britain's overcrowded jails.
It comes as the Home Office, facing a budget freeze, is ordering the Prison Service to slash its spending by ?240 million over the next three years at the same time as building extra places to cope with overcrowding.
Prisons chiefs are resisting the demand, claiming it is impossible to meet.
Lord Carter of Coles, a Labour peer, who carried out a review of prisons and probation in 2002, has been asked to sort out the impasse.
Indeterminate sentences have proved popular with judges, even for relatively low-level criminals. The judge sets a minimum term, or tariff, but the offender is only freed at that point if assessed as safe. One in five has a tariff of 18 months or less. Most are held in local prisons intended for short-term stays, which do not offer "lifer" rehabilitation programmes.
Paul Tidball, the president of the PGA, said: "The number of indeterminate sentences is far in excess of what was anticipated. They are a big contributor to the record numbers we have in prison.
"They are more resource-intensive, in terms of processing and assessing prisoners, than a determinate sentence. They are subject to assessment throughout, very much like someone serving an actual life sentence."
The prison population has risen from 61,000 to 80,000 under Labour, leaving jails full. Indeterminate sentences, introduced under the 2003 Criminal Justice Act, were intended to ensure that dangerous offenders spent longer behind bars. However, they were meant to be balanced by a 15 per cent across-the-board cut in the length of fixed-term sentences, which has not materialised.
Warders joined governors in attacking the sentencing reforms. Brian Caton, the general secretary of the Prison Officers Association, said: "Because of the sudden rise in prisoners serving indeterminate sentences, the system that we have, which is designed for a relatively small amount of lifers, cannot cope.
"The constant need to review indeterminate prisoners has a huge impact on the Prison Service. This is symptomatic of the appalling lack of planning the Government has applied to prisons."
The new-style sentences have also been criticised in recent weeks by Anne Owers, the Chief Inspector of Prisons, and Nacro, the charity that helps ex-offenders. Sir Duncan Nichol, chairman of the Parole Board, has said that as a result of their overuse, "prison overcrowding will increase and places on offending behaviour courses will be scarce".
Mr Tidball said it was "black humour" that the prison service should be required to build and operate new prison places, needed as a result of Government policies, from its existing budget.
The Government has admitted that indeterminate sentences are partly to blame for the prison capacity crisis. Explaining the causes of overcrowding two weeks ago, Tony Blair said: "You've got a situation where, today, people are in prison for longer and you've got, of course, new indeterminate sentences, where people can be kept for an indeterminate period if they remain to be a danger to the public."