Thousands of workers staffing job centres and benefit offices today vowed to stage a walk out later this month which would be the biggest civil service strike seen in a decade.
Members of the Public and Commercial Services union (PCS) voted strongly in favour of industrial action on January 29 and 30 across five government departments as a result of below inflation pay offers.
About 86,000 members at the Department for Work and Pensions, 4,500 staff at the Prisons Service and 150 workers at the Treasury solicitors office were balloted.
Members in the first two of these have already indicated that should there be no prospect of a negotiated settlement they will be going ahead with strike action on 29 and 30 January. Services which would be affected include job centres and the Child Support Agency.
Senior union officials in the Department for Constitutional Affairs, Home Office and Treasury solicitors office are meeting today to confirm what action to take following the outcome of the ballot.
The union said a clear message had been sent to ministers that the issue of low wages must be tackled and it was still hoped negotiations with the government would resume.
General secretary Mark Serwotka blamed a management "hell bent" on driving down pay: "This is not a decision our members have taken lightly."
He added: "The people being balloted on industrial action aren't your bowler-hatted Sir Humphreys. These are people who are low paid, delivering key frontline services and in many cases in receipt of the very benefits they hand out."
But a spokesperson for the Department of Work and Pensions said it had made a "substantial" offer - worth an average of 5% - which had been targeted towards more junior and less well-paid staff.
"Despite union suggestions, the department does not have any more money available to spend on salaries. We have a challenging programme of work to help some of the most disadvantaged people in the UK and need to ensure taxpayers' money is spent responsibly," the spokesperson said.