Hospital doctors in England on Friday launched a new walkout in a dispute with the government over pay in the latest strike action to hit the UK's state-funded National Health Service.

The four-day strike by junior doctors comes amid record patient waiting times due to a large pandemic backlog and strikes across the economy as workers demand pay rises in response to the worst cost-of-living crisis in a generation.

Junior doctors -- physicians who are not senior specialists but who may still have years of experience -- makeup about half of the doctors in UK hospitals.

Their industrial action will begin at 7:00 am and is scheduled to run until 7:00 am on Tuesday.

"This latest round of junior doctors strikes will again significantly disrupt services for patients," said National Health Service (NHS) medical director Stephen Powis.

"The additional challenge this time is that organizations are unable to use agency workers to cover staff out on strike," he added.

The British Medical Association (BMA) says the take-home pay of junior doctors who they represent has fallen by 26 percent in the last 15 years.

But the government says their demands are too costly.

Nurses, ambulance staff and other medical workers have all joined picket lines in recent months, mounting more pressure on the public health service.

According to NHS figures, close to 778,000 medical appointments have been postponed across the health service in England due to strike action since December.

"Patients are bearing the brunt of the impact of continuous strikes across the NHS, and further action by the BMA will cause more appointments and procedures to be postponed," health minister Steve Barclay said.

He said that a pay rise of six percent with an additional lump-sum of GBP 1,250 announced by the government mid-July was "final" and urged the BMA to "end its strikes immediately".

A record 7.6 million people in England were waiting to start routine hospital treatment in June, according to data published by the NHS on Thursday.