Accident and emergency waiting times in England have fallen to their worst levels for more than a decade, latest figures confirm.
Just published data shows just 92.6% of patients were treated within the four-hour time limit against a target of 95%.
It comes as a surge in demand at emergency departments has forced several hospital trusts to activate major incident plans.
Health Secretary Jeremy Hunt has admitted there is a “huge amount of pressure” on the health service.
Shadow Health Secretary Andy Burnham accused the Government of failing to tackle the crisis.
Sky’s Health Correspondent Thomas Moore said the waiting time figures were a sign of how emergency departments were struggling to cope with the huge rise in admissions, which have soared by a third over the last 10 years.
When broken down, the quarterly records show the country’s major A&E departments fared even worse, with fewer than nine in 10 patients – 88.9% – being seen within the target.
Dr Sarah Pinto-Duschinsky, director of operations and delivery for NHS England, said: “Today’s figures show that, in the three months to the end of December, more than nine out of 10 A&E patients in England continued to be seen and treated in under four hours – the best measured performance of any major Western country.
“In the immediate run-up to Christmas, the NHS treated 446,500 A&E attendees, up 38,000 on the same week last year.
“And there were 112,600 emergency admissions – the highest number in a single week since we started publishing performance figures in 2010.
“We faced similar demand over Christmas itself. In the week ending December 28 A&E attendances were up more than 31,000 on the same period last year, meaning we successfully treated more patients in under four hours than ever before.”
Hospitals were required to treat 98% of patients within four hours until 2010 but the Coalition scaled the target back to 95%.
The figures were released as a number of hospitals had major incident plans in place to cope with demand.
Gloucester Royal, Cheltenham General Hospital, Scarborough Hospital and the University Hospitals of North Midlands in Staffordshire have implemented the emergency measure.
Others, including the Royal Surrey County Hospital, urged people to stay away from A&E unless their case was a genuine emergency.