The branch has written to the minister and want her to visit the UKHO at its headquarters in Taunton, although they are prepared to visit her as well.

Branch president John Bird says the combination of the government’s pay freeze, the ban on pay progression, the pension tax and our bonus scheme means that morale amongst staff has never been lower.

“We have staff that are doing the same work with the same skills and experience, yet are being paid wages that in some cases vary by thousands of pounds. Recently our members voted in a ballot to withdraw their good will and work to rule.

The branch wants UKHO to replace its broken pay structure with something that functions and is fair.

Bird said: The UKHO contributes a dividend to the Treasury and staff deliver everything asked of them, year after year. We cannot allow this situation to continue or deteriorate further.

Prospect TV interviewed John Bird and negotiator Helen Stevens at the Ministry of Defence group annual conference in June.