Hundreds of contract staff in jobcentres will go on strike today in a dispute over job cuts.
Members of the Public and Commercial Services (PCS) union working in call centres, jobcentres and offices across the country will walk out for two hours from 9.30am.
They are employed by Balfour Beatty, providing the Department for Work and Pensions with telephone and typing services.
PCS general secretary Mark Serwotka said: "This dispute is a result of privatisation creating a two tier workforce.
"Balfour Beatty staff work alongside civil servants but are treated much worse. There has been no attempt to redeploy people facing redundancy and the terms on offer are the lowest the company can get away with and stay within the law."
A Department for Work and Pensions spokesman said: "Jobcentre Plus employees are not involved in this strike and we are working with Balfour Beatty. We have plans in place to ensure our services are maintained."