Fire officers working for MoD do not have access to the pension scheme that local authority fire officers can join and are admitted to the general pension scheme for civil servants instead.

Historically, salaries for MoD fire officers were adjusted to equalise net pay with that of local authority fire officers, because civil servants were not required to make pension contributions. This situation changed in 2012, with reform of the civil service pension schemes. Yet the adjustment to MoD fire officers’ salaries remains in place.

Written Parliamentary Questions from the SNP's Kirsten Oswald MP revealed that the deduction applied by the MoD allows for the lower member contributions but does not take account of the fact that the benefits in the civil service pension scheme are much less generous than the benefits for local authority fire officers.

The answers to the Parliamentary Questions also revealed that the Ministry of Defence does not know how the original deduction was calculated or how to adapt it to reflect changes since it was first applied.

Steph Marston, who has been leading Prospect's negotiations with the MoD, said: “The position is completely unfair. Our members are suffering a penalty on their salaries which is no longer justified by the facts. To add insult to injury, their pension scheme is far less generous overall than the local authority fire service scheme.

"The deduction that applies now is simply an arbitrary amount that the Ministry of Defence is unable to provide a rationale for. Prospect is in negotiations with the MoD and our members want the deduction scrapped, in recognition that the facts have changed.”

Further discussions on this issue will take place later this month.