The company, which makes the UK’s nuclear deterrent, had previously consulted on closing its defined benefit pension scheme to all staff and replacing it with a defined contribution alternative.

Prospect members voted overwhelmingly for industrial action over the initial proposals and have since carried out a 24-hour strike and have been working to rule.

In response, the company has presented a revised proposal that involves scheme members being able to obtain a significantly higher level of employer contribution to the proposed defined contribution scheme.     

Richard Tabbner, Prospect negotiator, said: “It’s disappointing that the revised pension proposals were only put forward after members went on strike and started on a work-to-rule.

“It’s even more disappointing that the company has not seriously engaged with the counter-proposals put forward by the trade unions because we do not believe the company’s proposals meet its criteria of ‘fair and affordable’ pension provision for all employees.

“However the latest offer does represent a significant development and Prospect representatives at AWE felt the responsible thing to do was to let members have their say in a ballot.

“The ballot closes on 13 December and the work-to-rule will continue during the ballot period.”

Prospect will write to the company to advise them of further subsequent strike action if members reject the revised proposals.

“Even at this stage, I would urge the company to seriously consider the improvements put forward by the trade unions as we believe they would help bring this dispute to a close,” concluded Tabbner.