Thousands of ambulance workers in Britain began a one-day strike on Wednesday, a day after nurses walked out, with unions and the government swapping accusations of blame for putting lives at risk.

The government advised people not to play contact sports or take unnecessary car trips in order to reduce their risk of needing an ambulance, as paramedics, call-handlers and technicians across England and Wales staged their biggest walkout in three decades.

Three ambulance unions were striking for either 12 or 24 hours. They have pledged to respond to life-threatening calls, but officials said they could not guarantee everyone who needed an ambulance would get one.

“The system will be under very severe pressure today,” health secretary Steve Barclay told Sky News. “We’re saying to the public to exercise their common sense in terms of what activities they do, being mindful of those pressures that are on the system.”

Stephen Powis, national medical director of the National Health Service in England, advised people not to get “blind drunk”.

“It’s the season of parties, pre-Christmas, so do enjoy yourself but obviously don’t get so drunk that you end up with an unnecessary visit” to a hospital emergency room, he said.

Healthcare staff and other public sector workers are seeking raises in the face of decades-high inflation that was running at 10.7 percent in November.

Prime Minister Rishi Sunak’s Conservative administration argues that double-digit public sector raises would drive inflation even higher.

Union leaders accused the government of deliberately prolonging the strike.

“I have never seen such an abdication of leadership as I have from Rishi Sunak and the health secretary,” said Sharon Graham, leader of the Unite union that represents some ambulance staff.

Nurses have also held two days of strikes this month, piling pressure on a health system that is already under strain from surging demand as pandemic restrictions ease, alongside staff shortages from burnout and Brexit, which has made it harder for Europeans to work in the UK.

Official statistics show that ambulances in many areas are routinely stuck waiting outside hospital emergency departments, sometimes for hours, because there are no beds for the patients.

Ambulance crews are due to strike again on December 28. Railway staff, passport officers and postal workers are also planning walkouts over the Christmas holiday season.

The UK’s most intense strike wave for decades is a response to a cost-of-living crisis driven by soaring food and energy prices in the wake of the COVID-19 pandemic and Russia’s invasion of Ukraine.

As a result of the industrial action, people across the UK face postponed hospital appointments, cancelled trains and travel delays during the winter holiday season. But opinion polls have suggested a high level of support for the workers.