Staff who survived the Con-Dems' public-sector jobs cull are now being worked to their limits, official figures showed today.
Public-sector labour costs per hour fell by almost 5 per cent in the last quarter of 2012 as a result of many people working beyond their contracted hours.
In comparison labour costs per hour in the private sector rose by 0.3 per cent.
A TUC spokesman said an "overstretched workforce" lay behind the fall in public-sector labour costs.
"The staff remaining are having to do more hours as colleagues are made redundant, as well as having their pay held down below inflation by the government's arbitrary freeze and cap," he explained.
"Some of these extra hours are not paid, with unpaid overtime on the increase across the public sector."
Hundreds of trade unionists joined a pre-Budget rally last week to demand Chancellor George Osbourne delivers a budget for growth.
And thousands of civil servants are to strike on Budget Day next Wednesday in protest at attacks on pay and pensions.
PCS general secretary Mark Serwotka told the Star: "Civil and public servants are working harder than ever to provide services that we all rely on, they are trying to help people back to work, collect taxes, advise on benefits and tax credits, and countless other jobs.
"But, instead of rewarding them, the government is cutting their pay, raiding their pensions and trying to rip up their basic terms and conditions."