Thousands of patients have had to wait in the back of an ambulance outside accident and emergency before being handed over to hospital staff.

Figures revealed under a Freedom of Information request to the London Ambulance Service by the Enfield Independent shows more than 4,000 ambulances with patients in are left waiting to be seen at North Middlesex University Hospital’s A&E, in Sterling Way, Edmonton.

From September to 2013 to September 2014 there were 4,798 occasions when ambulance crews had to wait more than 30 minutes to hand over patients.

In the thirteen months measured, an average 369 ambulances were kept waiting for more than half an hour to be passed onto accident and emergency.

The Edmonton hospital has come under scrutiny since the closure of Chase Farm Hospital A&E last December and has seen a boom in patients.

Incidentally, between December 2013 and April 2014, a huge spike of 2,280 ambulances waited longer than 30 minutes, almost 50 per cent of the total number in the 13 months measured.

The figures are almost four times that of ambulance waiting times Barnet hospital, which saw 1,292 ambulances wait more than 30 minutes to pass on patients to the A&E.

The hospital has felt the strain since the closure of Chase Farm’s A&E with health watchdog the Care Quality Commission in August stating that the A&E at the Edmonton hospital “required improvement” and that “more needed to be done by the trust to make sure good quality care was maintained.”

Last month figures were revealed that 1,898 people waited more than four hours at the hospital in the past three months.

Edmonton MP Andy Love told the Enfield Independent that the figures are “very concerning.”

He said: “It’s very concerning to learn just how many ambulances are kept waiting before handing over patients when they arrive at the North Mid.

“People arriving in ambulances are often in very serious conditions so the minutes really do matter.  The figures show that last year’s winter crisis impacted badly on queuing ambulances.

“The NHS is clearly stretched and how it will cope through this winter remains to be seen.  We need urgent frontline investment locally and nationally to prevent services being stretched to breaking point.”

A spokesman for North Middlesex University Hospital said: “Ambulance admissions have risen by 30 per cent in the eleven months since the local changes – from 88 to 113 on average each day – making us one of the busiest A&Es in London.

“Despite this increase, we have reduced the proportion of ambulances waiting more than 30 minutes from 11.4 per cent in September 2013 to 7.8 per cent in September 2014 - not least because we have worked hard with the London Ambulance Service and other NHS partners to achieve this and we are continuing to make further improvements."