A&E waiting times in March were the worst since records began, with figures also showing that 2017/18 was the worst year.
Hospitals struggled during the winter with particularly cold weather, including heavy snow, and high rates of flu and norovirus.
But while performance would usually be expected to improve in the spring, a higher percentage of patients than ever had to wait four hours or more to be seen upon arrival at A&E departments in England last month.
Just 84.6% of patients were seen within four hours overall, while only 76.4% of patients at major A&E departments were treated within the four-hour target.
The March statistics released by NHS England also mean 2017/18 is now confirmed as the worst since records began in 2003/04.
As well as A&E data, the figures also show the number of patients having to wait more than a year for treatment has now gone over 2,000 for the first time since August 2012.
They reveal that just 87.9% of patients started planned treatment within 18 weeks, meaning the 92% target has now not been met in two years.
Dr Nick Scriven, president of the Society for Acute Medicine, said the figures "are the clearest indication yet of the eternal winter we now face in the NHS".
He said he feared how hospitals would clear the backlog of cancelled operations, with some continuing to postpone planned procedures so they can prioritise patients needing emergency care.
Janet Davies, chief executive of the Royal College of Nursing, said "what began as a 'winter crisis' in the NHS is now becoming entrenched".
She said it was "shameful" that more than 75,000 patients who arrived at A&E had to be kept on trolleys for up to 12 hours while they waited for a bed last month, with more than 850 stuck on trolleys for longer than 12 hours.
"We need urgent answers as to why it has more than trebled in the last year," she added.