When ambulance crews bring patients to hospital they are meant to be able to handover their patients to A&E staff within 15 minutes.
But an analysis by the BBC shows by late November more than 11,000 ambulances were spending over an hour stuck in queues outside hospital every week.
That is one in seven of all arrivals and the highest since records began in 2010.
The BBC’s health editor Hugh Pym joined two members of South Central Ambulance on shift in Milton Keynes to see the problems this is causing first-hand.
In other news – Prince Harry and Meghan Netflix series behind closed doors
A trailer for Prince Harry and Meghan‘s Netflix documentary has been released, offering a first glimpse at what the couple says is the inside story of why they stepped down from royal duties.
“No one sees what’s happening behind closed doors,” said Prince Harry. When the stakes were this high, doesn’t it make more sense to hear our story from us?” Meghan adds. Learn more