Fears have been raised over patient safety and staff morale after January was the worst month for A&E performance since targets were introduced in 2004.
NHS England data shows 88.7 per cent of A&E patients were admitted, transferred or discharged in four hours, against a target of 95 per cent.
At Mid Yorkshire Hospitals Trust, which runs Pinderfields, Pontefract and Dewsbury hospitals, just 81.4 per cent were seen in four hours in January.
The trust had 19,256 A&E attendances, up from 19,024 in December.
More than 2,000 patients waited on A&E trolleys for more than four hours to be admitted - including six who waited more than 12 hours for a bed on one day at Pinderfields.
At Leeds Teaching Hospitals, A&E performance against the four-hour target was 87.8 per cent in January.
Hospital beds were also being occupied by people who needed to be transferred - causing further hold-ups in A&E - as NHS trusts faced delays in discharging patients.
There were almost 160,000 days of delays at English hospitals in January, the second worst on record.
At Calderdale and Huddersfield NHS Foundation Trust, 191 days of delays were caused by patients waiting for places in residential or nursing homes.
Another 233 days of delays happened as patients awaited care packages so they could return to their own homes.
The Royal College of Emergency Medicine (RCEM) said urgent action was needed to help hospitals and NHS staff.
An RCEM report on the latest figures said: “The picture revealed by this week’s data is one of relentless pressure.
“Nationally it is our view that urgent action to increase capacity within A&E departments is required.
“This is important, because international studies have consistently shown that lengthy waits in emergency departments are associated with increased deaths, lack of dignified care and stressful working conditions.
“This latter point relating to staff resilience and morale is increasingly discussed but seldom addressed. Failure to do so is the single biggest risk to future patient care and outcomes.”
The Department of Health said more than 5,000 more people were being seen in A&E every day compared to five years ago.
A spokeswoman added: “The NHS is very busy but this year prepared for winter earlier than ever.
“Hospitals are coping well under increased pressure, and compared to January last year saw 111,000 more people in A&E within four hours.”