Civil servants at the Department for Work and Pensions (DWP) are to strike later this week after a vote of no confidence in top officials.
In a ballot organised by the Public and Commercial Services (PCS) union, 97.7% of members said they had no confidence in the department's senior management team.
In a 35% turnout, just 753 of the department's 32,625 staff who voted in the ballot said they had confidence in the department's management.
The result of the ballot organised by the PCS among staff working in jobcentres, benefit offices, the pension service and the Child Support Agency reflects the angry mood of the department ahead of the two-day strike due to start on Thursday.
The walk-out will be the third in a long-running dispute over pay and a controversial performance scheme, which the union says is discriminatory.
Staff are also angry at plans to close 10 pension centres and 550 benefit processing sites, while huge job cuts across the civil service announced by Gordon Brown in the comprehensive spending review earlier this month may have further angered union members.
The PCS said it would write to the secretary for work and pensions, Andrew Smith, calling on him to intervene swiftly to restore staff's confidence in senior management.
Mark Serwotka, the general secretary of the PCS, said: "Members have sent a clear message that they no longer have any confidence in their senior management's bullying and belligerent approach."
He added: "Going on strike is a step that the union and its members don't take lightly, but faced with management's continuing intransigence over the discriminatory and divisive pay scheme and with remaining problems of low pay in this year's pay round, members have been left with no option."
