The Public and Commercial Services union said almost 250,000 workers will take part in a rolling series of walkouts and protests as it steps up its campaign against budget cuts.
A 24-hour strike will be held on March 20, the day Chancellor George Osborne presents the Budget to Parliament.
Further national stoppages will be held, of varying durations and targeting different parts of the civil service, with dates to be announced at a later stage.
Other forms of disruptive industrial action will also be held, and the PCS said it will seek to co-ordination with other unions on pay and pensions.
More top news
The outspoken Birmingham MP tweeted a picture of locksmiths ramping up security at her home after facing fresh intimidation on social media.
Islamic State's Amaq news agency released footage showing French attacker Abdel-Malik Nabir Petitjean urging Muslims to destroy the country.
Brighter skies developing across northern Britain and Northern Ireland with some sunshine tomorrow but feeling cooler again.