Tory cuts are forcing ambulance bosses to pay millions a week in overtime as they plug staff shortfalls.
Emergency demand has hit record levels and overtime payouts are up 17 per cent since 2015 – costing the taxpayer some £800million.
Each trust is paying an average 4,500 staff overtime every year.
Last year alone, the North West Ambulance Trust spent £21million on overtime pay across 6,200 employees.
But GMB national officer Rachel Harrison said the figures are the “tip of the iceberg” and the cash should be invested in more full-time staff.
She added: “Ambulance workers do difficult jobs and the pressures are growing.”
One West Midlands Ambulance Trust paramedic said he has done shifts as long as 16 hours.
He said: “It’s a struggle. We’re always flat-out.”
The findings pile pressure on Prime Minister Boris Johnson after a Labour vow to outspend the Tories by £6billion a year on health.
Ambulance services in England have more than 2,000 vacancies, according to NHS statistics.
Yet nearly 800,000 calls were received and answered in October.
Shadow Health Secretary Jonathan Ashworth said: “The NHS is in crisis after nearly a decade of Tory cuts.
It’s a disgrace its dedicated ambulance staff are having to pick up the pieces.” The Department of Health refused to comment.
