Acas has struggled to resolve its own workplace dispute

Members of the Public and Commercial Services union (PCS) voted by almost two to one for a rolling programme of one-hour strikes.

Union members say the service failed to make a pay offer last year.

Publicly-funded Acas works to resolve workplace disputes. Unions warn that failure to resolve its own workplace dispute could embarrass the government.

"The failure of any pay offer and the lack of substantive negotiations have forced the very people who resolve industrial disputes into voting for strike action themselves," said general secretary Mark Serwotka.

"The government can avoid embarrassing and damaging strike action in Acas and elsewhere in the civil service by addressing low pay and paying a fair wage."

On its website, Acas says it "aims to improve organisations and working life through better employment relations".