The stoppage, between 10. 30am and 11. 30am hitting offices across the UK and the ACAS helpline, follows delays in settling this year’s pay and a pay offer of 2% which will result in real term pay cuts.

This year’s pay increase was due on 1 August and follows a 10-month hold up to last year’s 2007 pay increase.

This comes as 270, 000 PCS members from across the civil and public services vote on a programme of national industrial action over the government’s policy to cap public sector pay to below inflation.

In the strike ballot running to 17 October, members are being be asked to back plans for a national civil service wide strike followed by a programme of targeted industrial action that will extend into the new year.

Mark Serwotka, PCS general secretary, said: “It is ironic that the people who help resolve industrial disputes have themselves been pushed into taking industrial action by unacceptable delays and a pay offer that represents a real terms pay cut.

“The situation in ACAS is symptomatic of the government’s policy towards public sector pay which is creating financial misery for hardworking families. That is why we are now balloting our members across the civil service and related areas to take industrial action. It is time that the government reviewed its draconian pay policy and paid a fair wage to the people who keep this country working.”