Whitehall departments have had to pay millions of pounds extra in severance packages after their cost-cutting redundancy programmes attracted more applicants than expected.
The Ministry of Defence's bill for cutting staff in line with the austerity programme rose beyond £300m in the last financial year – more than double the amount originally allocated. The Department for Education spent £7.7m to fund 141 extra voluntary redundancies.
The austerity drive yielded 44,000 job losses last year, at a cost of more than £600m in lump-sum payments and pension packages.
A Treasury spokesman last night said the higher redundancy bills would, in the long run, save money through reduced wage bills.
But Mark Serwotka, of the PCS union, said: "The solution is not to cut even more jobs, but to invest in staff and resources to improve public services and help our economy."