Tavistock MP Sir Geoffrey Cox is calling for assurances that Dartmoor Prison will not be permanently closed down.

He has written to the new Secretary of State for Justice Shabana Mahmood MP as the prison is temporarily shut down due to radon.

All 175 prisoners remaining at the Napoleonic jail in the middle of Dartmoor will be moved to other prisons by the end of July.

This will allow ‘remedial action’ to allow for ventilation of the prison, a source at the Prison Officers’ Association said.

Sir Geoffrey wrote: “We are led to believe that this closure is temporary, but I am puzzled why, in the light of the shortage of prison places, the Government has given in to demands to evacuate the prison because of radon gas. That problem has been known for several years, mitigating measures were being taken, and the Conservative Government did not accept the Health and Safety Executive’s suggestion that the gas infringed the legal standards of exposure or was a substantial risk to prisoners.

“I am seeking urgent explanations and assurances that the necessary action will be taken to reopen the prison as soon as possible. When I visited last year, I found a well-run prison and a dedicated staff. It makes no sense at all for this prison to be closed without the most compelling reasons and it is vital for the staff and their families that the uncertainty is removed soon.”

A spokesperson for the Ministry of Justice said that the new Government would be ‘setting out its long-term plan for prison capacity later this year’.

Meanwhile legislation is progressing through the House of Commons to allow the Government to release prisoners early from the nation’s overcrowded jails.