Accident and emergency departments in England have failed to meet the target of 95% of patients seen within four hours for the 20th week in a row.
NHS England said 91.6% of patients spent four hours or less from arrival to admission, transfer or discharge in the week ending February 15, down from 92.9% the previous week.
It came as the level of admissions reached its highest levels since the peak seen at Christmas with 420,700 patients - up from 407,000 the previous week.
It is the 20th week in succession that the four-hour goal of 95% has been missed.
The number of emergency admissions was also up to 107,200 from 105,500 the previous week and up on the 104,500 peak seen last year.
More than 8,890 people had to wait more than four hours , up from 7,280 the previous week.
Dr Barbara Hakin, national director of commissioning operations for NHS England, said: "Last week saw a sharp increase in A&E attendances and emergency admissions - up by nearly 15,000 on the week before. These are the highest levels since Christmas and are also up on the same week last year.
"This has resulted in a slight impact on waiting times, but we continue to admit, treat and discharge more than nine out of 10 patients within four hours."
In the week leading up to Christmas, A&E departments saw an unprecedented peak of 446,473 attendances.
Public Health England said there were similar levels of flu to the previous week - particularly in the elderly.
There has also been significant excess mortality this week among those aged 65 plus, coinciding with circulating flu and the recent cold snaps.
Cold weather alerts have been in place across the country since January 12.
There have also been small increases in reported incidents of diarrhoea and vomiting in hospitals, although these are at similar levels to previous years.
The number of instances of ''bed-blocking'' was the same as the last week, with 4,000 hospitals beds unavailable for incoming patients because of delays in transfers of occupants to care elsewhere.
The NHS 111 phoneline had 270,000 calls in the week ending February 15, up from 251,000 in the previous week, but significantly down on the peak of 439,000 for the week ending December 28.
Shadow health minister Jamie Reed said: "Today's reports paint a clear picture of an NHS heading downhill under this Government.
"David Cameron caused the A&E crisis by taking social care support away from hundreds of thousands of vulnerable older people while his reckless NHS reorganisation is still disrupting cancer care.
"He should now back Labour's five-point plan for A&E and match our plans to invest an extra £2.5 billion each year to give the NHS the staff it desperately needs."