The company was the winning bidder in the recent contracting out exercise and it has announced that it will reduce staff numbers from nearly 600 to under 400 when it takes control of the prison.

Prospect negotiator Richard Hardy said that although SJS had a good track record in running its own purpose-built brand new prisons, HMP Northumberland was an old RAF base not designed for custodial use and far removed from SJS’ experience.

“Any operation losing one third of its staff causes severe concern. Nearly 100 prison officer jobs will be lost and of course this is also a real concern to the POA.”

Hardy said programmes to address prisoner behaviour would be threatened by planned reductions to prison psychology staff, chaplains and the offender management unit.

“The prison is the biggest employer in the area and the loss of 200 jobs is a major blow to the local economy and the community. We will work hard to avoid compulsory redundancies.”