Union Prospect said it is the first time a ballot on industrial action has taken place at the Civil Aviation Authority.
Workers at the Civil Aviation Authority (CAA) are to be balloted on industrial action in a dispute over pay.
Prospect said it is the first time a ballot on industrial action has taken place at the CAA.
The union said CAA staff have been facing a cost-of-living crisis, with pay having fallen in real terms by 37.2% since 2011.
Prospect said its members have been offered a 5% pay rise for the coming year.
Prospect general secretary Mike Clancy said: “More than a decade of real-terms pay cuts have led to a cost-of-living crisis for our members at the CAA.
“Their goodwill in taking a pay cut during the initial stages of the pandemic to enable their employer to continue to function has not been met in kind by the CAA.
“We will not hesitate to take industrial action to win a better deal for our members and restore the CAA’s status as a world-class aviation regulator.”