Tens of thousands of nurses and ambulance service staff walked off the job on Monday in a pay dispute, putting further strain on Britain’s state-run National Health Service with their largest ever strike.

Nurses and ambulance workers have been striking separately since late last year but Monday’s walkout involving both, largely in England, is the biggest in the 75-year history of the NHS.

“The government needs to listen and discuss pay rather than just saying the NHS doesn’t have money,” said nurse Ethna Vaughan, who was part of a demonstration outside St. Thomas’ Hospital in central London.

“We cannot survive with what we’re being paid.”

ibtimes Workers stage largest strike in history of Britain’s health service