Public sector employment as a share of the labour market has fallen to a 70-year low, new figures show.
Almost 17% of all workers are employed in the public sector, the lowest figure since 1947, said the GMB union.
Almost one million public sector jobs have been lost since 2010 due to funding cuts, privatisation and outsourcing, mainly in local government, a GMB study found.
National officer Rehana Azam said: “These shocking figures are a stark reminder of the scale of the catastrophe befalling our public services.
“Any sensible opportunities for efficiencies are long gone, funding reductions are now cutting into sheer bone.
“GMB’s members are performing miracles but the vital services they deliver are being stripped-back and hollowed-out and denied the resources they need, and workers are being denied the fair pay rises they deserve.
“We should celebrate the fact that people are living longer, but if services don’t get additional funding then crises of provision are inevitable.
“That breaking point has already arrived in the NHS and social care.”
The research comes amid continued union anger over the pay cap on public sector workers.
The Government announced the cap will be lifted for police and prison officers but no decision has been made about millions of other public sector employees.
Unions representing more than a million health workers are pushing for an above inflation pay rise in a direct challenge to the government.