On behalf of civilian specialists in Babcock, negotiator Richard Hardy said: “The announcement recognises the amazing work done by Prospect members on the Clyde and is a tribute to the quality of their work and commitment.”

“The drawn out nature of the negotiations added to the uncertainty around the future of the base caused by the Scottish independence referendum debate. Now the contract is signed our members can get on with their vital jobs.”

However, Prospect is concerned about the need to meet the £320m cost saving targets set out in the contracts, said Hardy.

“We are committed to working with Babcock to address this, but the savings can’t be achieved by simply cutting the pay, conditions and safety of our members and other staff.”

MOD says over 7,500 jobs will be safeguarded. The new contract covers the maintenance and repair of the Royal Navy’s warships and submarines. Babcock, which manages the naval bases at Devonport and Clyde has been awarded a £2.6bn contract. BAE Systems, which manages Portsmouth naval base has been awarded a £600m contract.