It's been confirmed that Dorchester Prison is to close and discussions are underway to end the lease at Dartmoor Prison.
Elsewhere, Portland's Verne Prison will be turned into an immigration detention centre.
The former Victorian military barracks, transformed into a jail more than 60 years ago, will become a Home Office immigration unit housing people waiting to be removed from the UK.
Duncan Sleightholme reports:
The Conservative MP for South Dorset Richard Drax said he was pleased the building would remain open with the prospect of more employment:
The Justice Secretary Chris Grayling said the prison will be turned into an immigration removal centre:
Existing staff will continue to run the site but the Home Office will meet the costs of its operation. Offenders housed at The Verne will be moved to other suitable prison accommodation.
The Ministry of Justice will begin to end the lease on HMP Dartmoor.
The site has a ten-year lease notice period but the MoJ said the age and limitations of the prison mean that it does not have a long-term future in a modern, cost-effective prison system.
HMP The Verne on Portland is to close as a prison and be converted into an immigration removal centre.
It will provide around 600 additional places to hold immigration detainees awaiting removal from the country.