LONDON (AFP) - Junior doctors in England started their first ever all-out strike on Tuesday (April 26) in a bitter, deadlocked row with Prime Minister David Cameron's government over pay and conditions.
The strike will have a major impact on the National Health Service (NHS), which employs thousands of junior doctors - graduates with years of experience who have not yet completed their professional qualifications.
While there have been several recent stoppages, this one will affect hospital emergency care units such as accident and emergency and maternity units for the first time, although senior doctors and nurses will still be on duty.
Nearly 13,000 operations and 113,000 appointments have been postponed around the period of the strike, which runs from 8am to 5pm on Tuesday and Wednesday.
"Anything unprecedented like this places a significant pressure on the NHS," Ms Anne Rainsberry, national incident director for NHS England, told BBC Radio 4.
"The NHS has done everything it possibly can to mitigate that, but you can never say that it has mitigated it completely," she added.
The British Medical Association (BMA), the doctors' trade union, has not ruled out a permanent strike or mass resignations as a way of trying to force the government's hand.
One junior doctor Ben White resigned live on national television on Monday to work on a legal challenge to the government's position, citing "understaffing and underfunding".
"I feel that I've got an obligation to do that on behalf of my patients," he said. "We've been backed in a corner."
The taxpayer-funded NHS, established in 1948, is one of Britain's most respected institutions, providing largely free medical care.
While it has been protected from austerity cuts to public services under Mr Cameron, experts warn it still faces increasing financial strain due to factors like rising treatment costs and an ageing population.
Mr Cameron's government argues that reforms to junior doctors' contracts are necessary to ensure that the quality of care for patients is as high at weekends as it is during the week.
The Prime Minister has quoted research claiming mortality rates for patients admitted to hospital on a Sunday can be 16 percent higher than on a Wednesday, though doctors question this.
An Ipsos Mori poll for BBC News found that 57 per cent of the general public supported the doctors, while a quarter opposed their actions.
Health Secretary Jeremy Hunt announced in February that he intended to impose the new contract on junior doctors after they rejected his "best and final offer".
A key sticking point has been on how much financial compensation junior doctors should get for working on Saturdays.
Hunt launched a last-ditch appeal to them to stop the strike in the House of Commons on Monday, saying: "The impact of the next two days will be unprecedented."
Mr Cameron's spokesman also urged them to think again.
"The question for the BMA is whether it is an appropriate or proportionate response to be refusing care for emergency cases over parts of their new contract," she said.
But there are signs the dispute is getting more entrenched as it goes on.
The health spokesman for the main opposition Labour party, Ms Heidi Alexander, said there was "no trust left" between Mr Hunt and junior doctors.
She compared his handling of the strike to "pouring oil on a blazing fire".
"Both sides seem to be digging in their heels," said Ms Katherine Murphy, chief executive of the Patients Association.
"They must now put aside their past stances and get together round the table to find a way forward in order to end the uncertainty that patients are facing."