A ballot of the union’s 1,220 members, including inspectors, scientists and other specialist staff in the safety regulation body, saw 60% of respondents vote in favour of a strike, while 85% backed action short of a strike.

The dispute follows the branch’s rejection of a 1% pay offer – a cut in real terms after successive years of pay freezes and pay caps. HSE imposed the offer last month even though it was overwhelming rejected by staff.

Prospect negotiator Jez Stewart said: “The result clearly demonstrates the growing dissatisfaction among HSE staff over the government’s continuing policy of civil service pay restraint.

“HSE staff do not take industrial action lightly. But the results of this ballot show that they have had enough of working harder than ever but seeing their living standards fall.”

Stewart said the branch’s senior representatives will meet on Wednesday 10 December to discuss the types of action and possible dates for both strike action and measures short of a strike.

 “We have notified HSE managers of the result and urged them to return to the negotiating table with an improved offer or risk further deterioration in employee relations among an already demoralised staff,” Stewart added.