A union has accused the Department of Work and Pensions of "cynically delaying" a redundancy announcement until hours after a strike vote closed.
The Public and Commercial Services Union (PCS) said the department had launched a voluntary redundancy scheme on Tuesday for staff at 13 sites.
The PCS said hundreds of jobs are now at risk in offices across the country, including Exeter, Milton Keynes, Aberdeen and Southend-on-Sea.