Civil service staff at the Department for Work and Pensions are planning a walkout on 16 and 17 February.

The Public and Commercial Services Union (PCS) accused the department of insisting on pressing ahead with "unacceptable performance appraisals".

The action will hit pensions, job centres and the Child Support Agency, threatening delays to benefit payments

'Poverty pay'

The PCS union said its members were "very angry" that there had been little progress in the pay talks.

It is now almost certain that more than 85,000 people in the Department for Work and Pensions will stage a walkout.

"The unwillingness of managers to engage in meaningful negotiations meant that industrial action was inevitable," said union leader Mark Serwotka.

The main issue is what the PCS calls "poverty pay" in the service.

And members are said to be angry that below-inflation pay rises were imposed before staff had voted on whether to accept them.

Talks are still going on with two other government departments following strikes earlier this month.