A prison holding more than 2,000 inmates, which would be Britain’s largest, could open under a plan that would see six existing prisons in England close.
The Ministry of Justice is to begin a feasibility study on developing a so-called super-prison in London, the north west or north Wales.
Meanwhile prisons at Bullwood Hall, Canterbury, Gloucester, Kingston, Shepton Mallet and Shrewsbury will close, while Chelmsford, Hull and Isle of Wight will see some accommodation reduced.
Some 2,600 places will be lost under the plan which is part of a drive to build new capacity to replace older prisons and cope with record numbers of inmates and bring down the cost of the prison system. It is expected to save £63m a year.
Justice Secretary Chris Grayling said: “We have to bring down the cost of our prison system, much of which is old and expensive. But I never want the courts to be in a position where they cannot send a criminal to prison because there is no place available.
“So we have to move as fast as we can to replace the older parts of our prison system.”
We have to move as fast as we can to replace the older parts of our prison system. Justice Secretary Chris Grayling
In addition to the super-prison Mr Grayling has unveiled plans for four new mini-prisons known as houseblocks.
These would be built at existing prisons at Parc in south Wales, Peterborough in Cambridgeshire, the Mount in Hertfordshire, and Thameside in London. In total they will be able to hold up to 1,260.
The announcements come just a day after the government said it was planning a major shake-up of the probation system, with prisoners sentenced to less than 12 months being obliged to undergo rehabilitation. Under the plans private companies and charities will run much of the rehabilitation work, with many fewer prisoners under the automatic supervision of the probation service.