Busy NHS hospitals saw their worst ever performance for waiting times at major A&E departments last month, according to figures released this morning.
Just 77.1 per cent of emergency patients were either admitted to hospital, transferred or discharged within hours, against a national target of 95 per cent.
Figures released by NHS England also show that 81,000 patients had to wait on trolleys in A&E for more than four hours, and more than 1,000 waited for more than 12 hours.
Dr Nick Scriven, president of the Society of Acute Medicine, said measure were needed to tackle stress and exhaustion among NHS staff.
He said: "The last six weeks has seen the acute services of the NHS under a sustained period of stress due to normal winter pressures along with a surge in influenza.
"Neither of these were unpredictable but both have combined to cause the issues that have been widely reported across the country."
The 77.1 per cent figure for Type 1 A&E departments, those staffed by consultants providing 24-7 emergency care, was the lowest on record, down from 77.3 in December.
The number of patients waiting more than four hours in all A&E departments, including minor injuries units and specialist centres, was 85.3 per cent.
At Leeds Teaching Hospitals NHS Trust, 68.9 per cent of all A&E patients were seen within four hours last month, down from 79 per cent in December.
The January figure was 78.8 per cent at Mid Yorkshire Hospitals Trust, down from 82.8 per cent from the previous month. At Mid Yorkshire almost 2,000 patients waited on trolleys for more than four hours, up from 1,414 in December.
The four-hour figure for Hull and East Yorkshire NHS Trust fell from 82.4 per cent in December to 77.7 per cent in January.
NHS England said more than 1.7m patients were seen within four hours last month, an increase of 5.72 per cent on the daily average for the same month last year.
There were 36 cases of ambulances being diverted to other A&E departments last week, compared with 43 in the previous week.
An NHS England spokesman said: "Despite the worst flu season in seven years, A&E performance improved this month.
"It was better than both the month before, and was better too than the same time last winter.
"This was partly helped by the fact that NHS-related delayed transfers of care fell to their lowest in four years freeing up beds for patients needing emergency hospitalisation."