Thousands of junior doctors across England today began a 48-hour strike in a row with the Government over a new contract.
More than 5,000 operations and procedures across England have been cancelled ahead of the 48-hour strike, which began at 8am.
Health Secretary Jeremy Hunt has announced he will impose the contract on junior doctors - everyone up to consultant level - after months of talks with the British Medical Association (BMA) failed to reach a resolution.
Junior doctors will provide emergency care only on Wednesday and Thursday, with two further 48-hour strikes planned from 8am on April 8 and April 26.
The third strike by the BMA comes as an Ipsos MORI poll for BBC News found 65% of members of the public support the doctors' cause.
The survey found most people still think the Government is most at fault for the dispute, but a rising number believe equal blame should be shared by the Government and doctors' leaders.
Public support for the latest strike is as high as it was for the first two stoppages earlier this year, with 65% of 860 adults in England supporting the strike.
Some 57% said the Government was most at fault for the dispute continuing this long, down from 64% in February, while the number saying junior doctors were most at fault remained around 11%.
New figures from NHS England from 228 organisations, of which 154 are acute hospital trusts, show that 2,077 inpatient procedures have been cancelled due to today and tomorrow's industrial action alongside 3,187 day case operations and procedures.
Hundreds more routine clinics and appointments are likely to be affected.
Dr Anne Rainsberry, national incident director for NHS England, said: "This is clearly going to be a difficult couple of days. A 48-hour strike will put significantly more pressure on the NHS and the cumulative effect of these recurring strikes is likely to take a toll.
"The safety and care of patients is always our number one priority and staff across the NHS are doing all they can to minimise the impact on patients of the action."
Urgent and emergency care services will be available as normal but hospitals are expected to be under extra pressure
Where possible, patients are being asked to contact their GP, seek advice from their local pharmacist, call 111 or check the NHS Choices website.
In an emergency, people should still call 999 or go to A&E.