The number of patients having to wait in an ambulance for more than two hours before being admitted to hospital has quadrupled in the last three years, according to new figures.
Crews spent more than 400,000 hours waiting longer than the national target of 15 minutes for a patient to be taken into hospital, a Freedom of Information request by the Liberal Democrats found.
The figures, shown to ITV's Good Morning Britain (GMB), revealed that more than 700,000 people waited over an hour before they were admitted.
The longest handover - in the West Midlands - was more than nine hours, while in one month 146 patients at Leicester Royal Infirmary had to wait for more than two hours because staff at the hospital were too busy to admit them, GMB said.
Eight out of 10 trusts have reported delays, which the Lib Dems say is costing the NHS around £31 million a year.
The party is calling for an independent cross-party commission to examine the NHS and social care system.
Lib Dem health spokesman Norman Lamb said the lost hours are "completely unacceptable" and reflected a "crazy way to run the system", warning that the Government was "sleepwalking" towards a crash and patients would pay the price.
He told GMB: "This is unsafe care and unless the Government grasps this and does something about it then we are going to see patients suffer."
Mr Lamb, who until last year was minister of state for care and support in the coalition government, said the NHS needed more money.
He said: "We are projected to spend a reducing percentage of our national income on our health system.
"Around Europe we are now spending significantly less on our NHS than other comparable countries. I think we just have to have a mature discussion with the public - how much are we prepared to pay through our taxes to ensure that we have a good health and, critically, care system as well.
"I argue for a dedicated health and care tax so people know where their money is going."
A spokeswoman for NHS England said: "A&E departments do sometimes come under pressure and there are occasions when it is appropriate and best for the patient that their handover is delayed while they are, of course, still receiving care from skilled ambulance staff.
"In many areas financial incentives have been introduced alongside measures to reduce handover delays, and we expect to see results from these over the coming months. Staff work hard to keep these occurrences to a minimum."