The waiting list for NHS hospital care in England has reached another record high, and health service bosses say “skyrocketing” demand is likely to make treatment delays even worse.

The number of people waiting for surgery or other procedures in hospital rose to almost 6.4 million at the end of March, NHS England’s latest performance data shows, up from 6.2 million in February and the highest total since records began in 2007.

Siva Anandaciva, the chief analyst at the King’s Fund health thinktank, said NHS-wide staff shortages were hampering the service’s ability to give patients timely care.

This week’s Queen’s speech identified tackling the NHS backlog as one of the government’s key priorities, but “until ministers grasp the nettle on health and care staffing shortages it will be patients who continue to pay the price by waiting longer in discomfort, pain and deteriorating health”, he said.

The figures confirm the mismatch between demand for care and the NHS’s ability to provide it quickly, especially in A&E units, responses to 999 calls and planned care.

Matthew Taylor, the chief executive of the NHS Confederation, which represents health service trusts, said the situation at the frontline was deteriorating.

“Services are working together to put the additional investment from the government to best use, but they are doing so in increasingly intolerable circumstances, with 110,000 vacancies and patient demand skyrocketing,” he said.

“Leaders are concerned that unless more support and greater acknowledgment to the reality facing frontline care given, then delivery against these vital targets could crumble.”

The number of people waiting more than two years for hospital care fell from 23,281 in February to 16,796 in March, a drop of 28%. NHS England and the Department of Health and Social Care have pledged to eradicate two-year waits by July, but health service executives believe the target will be missed.

Prof Stephen Powis, NHS England’s national medical director, said the two-year figures showed that “hardworking teams across the NHS are making good progress in tackling the backlogs.”

The number of people waiting at least 18 months also fell, but the backlog of those forced to wait a year or more for surgery rose again from 299,478 to 306,286.

Powis said it was unsurprising that the waiting list had continued to grow because NHS bosses assumed people who held off seeking care during the Covid-19 pandemic would at some point want the health service to investigate their symptoms.

The data also showed that:

* A record 24,138 people had to wait at least 12 hours in A&E between the decision to admit them and their getting a bed.

* Only 72.3% of people attending A&E were seen within four hours, far below the 95% target.

* Ambulance response times remain poor, with crews taking longer than they should to attend emergency and urgent calls.

* An average of 12,589 beds were filled with patients who were medically fit to be discharged during March, which limited hospitals’ ability to admit patients and perform planned surgery.

The number of children and young people waiting for urgent eating disorder treatment for conditions such as anorexia and bulimia has also risen to record levels. There were 249 waiting to start urgent treatment at the end of March, up from 130 at the same time last year.

Chris Hopson, the chief executive of hospitals body NHS Providers, said the health service was struggling because of issues outside its control, namely a 10-year budget squeeze, lack of capacity in hospitals to treat the number of patients turning up, major staff shortages and inadequate provision of social care.