The Conservative leader David Cameron today pledged a prisons policy where inmates have to "earn their release" as he unveiled plans to build 5,000 additional jail places.
Mr Cameron said the Conservatives would introduce new "min-max" sentences, setting a minimum and maximum period behind bars, with no possibility of parole until the minimum term has been served.
"Prisoners have to earn their release. Today, I think almost everything with the system is wrong," he told BBC Breakfast.
"A criminal goes to court, they are told they have got a four-year sentence and they are let out after two, so everybody feels cheated.
"We are going to change that and say the judge should read out what we call the 'min-max'...
"And then the prisoner has to earn release through good behaviour, through hard work, through making reparations to their victims."
He added: "The real emphasis on it is actually turning prisons into places, not where we just warehouse prisoners, and bang them up for 23 hours a day in their cell, but they should be places of work, of rehabilitation and of reparation, so that the work prisoners do do, means that they can pay money back to their victims - these are really important policies."
The Tory plans, set out in a "Green Paper", would mean the additional capacity will be used to end the system of automatic release for prisoners after they have completed half the jail term handed down in court.
The new "min-max" sentences would set a minimum and maximum period behind bars, with no possibility of parole until the minimum term has been served.
The proposals - taken on top of existing Labour plans for new jail places - would take the total prison capacity in England and Wales to more than 100,000 for the first time.
The Conservatives say that they can finance the plans from within the existing prisons budget by selling off old, unsuitable jails on high-value land for redevelopment.
The revenue raised will pay for the building of efficient new modern jails elsewhere.
Under the new min-max sentences, prison governors will decide exactly when inmates are released, depending upon their conduct in jail.
Those prisoners who prove the most unwilling to engage in rehabilitation programmes or stay off drugs will remain in custody the longest.
At the same time, the Tories say they want to introduce "purposeful regimes" where prisoners are made to work and acquire skills to make them more employable when they are released.
Shadow justice secretary Nick Herbert said: "Under Labour, re-offending by criminals has risen, jails are in crisis and over 18,000 prisoners have been released early on to the streets. A new approach is desperately needed.
"We will create prisons with a purpose, with a new focus on rehabilitating prisoners before and after their release. By driving down reoffending, we will break the cycle of crime and make Britain a safer place."
Prisons Minister David Hanson said: "This is yet another uncosted spending commitment from the Tories.
"The Conservatives' plans come amid the biggest prison building programme in history.
"Most of their proposals seem to be either way behind what we are doing already, schemes they have already announced or uncosted spending pledges.
"Coming on the back of a series of uncosted tax and spending commitments that the Tories have already made, the challenge for David Cameron and George Osborne will be to explain how they can pay for any of this."
Juliet Lyon, director of the Prison Reform Trust, said: "Successive governments have allowed prisons to rot in a policy vacuum. Now the Conservatives are turning the spotlight on our most neglected and least visible public service, this Government must reach beyond party politics and, instead of arguing about who can spend most money on more jails, it should establish a Royal Commission on the nature and purpose of imprisonment."Reuse content