Prospect union members at the Health and Safety Executive (HSE) have launched a campaign of industrial action against an imposed 1 percent pay deal.
They voted by 59 percent for strikes and by 85 percent for action short of a strike on a high 55 percent turnout.
The action starts on Thursday 18 December at 1pm for a half-day strike by inspectors, scientists and specialists based at 27 offices across Britain.
Action short of strike will start in the new year.