Labour has criticised hospitals as "too full" after figures claimed almost 300,000 ambulances were left queuing outside hospitals last year.
A patient was forced to wait for eight hours and 11 minutes in the West Midlands in the worst "handover delay", while another in the south west faced a seven and a half hour delay, research by Labour found.
Figures obtained through a Freedom of Information request found 279,207 ambulances were delayed for more than 30 minutes, with a further 30,601 waiting longer than one hour.
"Handover delays" occur when emergency wards are too busy to accept new patients due to staff or bed shortages, leading to patients facing delays in ambulances.
Shadow health minister Jamie Reed said the crisis in A&E departments was forcing "vulnerable patients" to be held in the back of ambulances.
More top news
The Prime Minister has rubbished the claim from the former London mayor that British troops were 'discredited' after Iraq and Afghanistan
Brothers Andy and Jamie Murray have beaten Belgian pair David Goffin and Steve Darcis to take a 2-1 lead in the Davis Cup Final
Protesters gathered outside Downing Street to urge MPs to vote down plans to bomb the war-torn country