The prospect of more civil servants going on strike over pay, jobs and conditions has increased after members of another union indicated support for industrial action.
Members of the Prospect union across government departments and other areas including the Health and Safety Executive and the Met Office said they would back action.
Another ballot will have to be held before strikes can go ahead.
Members of the Public and Commercial Services union are already involved in a campaign of strikes in the same dispute.
Prospect said it was the first time it has held such a ballot on industrial action across a range of public sector employers since the 2011 pensions dispute.
Mike Clancy, general secretary of Prospect, said: “This is a workforce that has been pushed too far. Industrial action is always a last resort, but staff have had enough of their hard work being taken for granted while their living standards have been under sustained attack for more than a decade.
“Ministers need to act. They must lift the 3% cap on the offers employers are able to make to allow meaningful negotiations to take place, and they must abandon their plans to slash redundancy terms.
“If they don’t, we will be moving to formal ballots which our members have shown they will support. We are prepared to do whatever it takes to get a fair deal for our members.”