More people are leave A&E at Norfolk's biggest hospital after waiting just minutes less than four hours than at any other time, sparking concerns that targets are taking priority above patient care.

Concerns have been raised that patients in A&E at Norfolk's biggest hospital are being put at risk to meet targets.

More people leave A&E at the Norfolk and Norwich University Hospital just minutes before the four-hour national target than at any other time, sparking concerns that targets are taking priority over patient care.

And in the year to the beginning of April, 2,495 people waited longer than the national standard of four hours in A&E at the N&N - 3.3pc of the total. The government target is that 98pc of patients should be seen within four hours.

The hospital has released the waiting times of all 75,863 A&E patients for 2008-09 after a Freedom of Information request from the North Norfolk MP Norman Lamb.

Mr Lamb is concerned that many patients spend more than three hours 50 minutes and less than four hours in A&E. In all, 5,668 patients spent this length of time in A&E, 7.5pc of the total and more than 50pc more patients than any other 10-minute period. The time stops being measured when the patient leaves A&E, either by going home or being admitted to hospital.

Mr Lamb, Liberal Democrat health spokesman, said: "There is a clear spike at three hours 50 minutes, which inevitably raises concerns. There are potentially dangerous consequences. Someone who is sent home too soon and deteriorates after leaving can be put at risk. Or they may be admitted inappropriately, which puts pressure on the hospital.

"I am not blaming the hospital - it is a consequence of the bullying culture that surrounds this target from strategic health authorities and government."

The N&N has the busiest A&E department in the region. Its official figure for 2008-09 is that 97.98pc of patients were treated within four hours, which was just 28 patients short of the target. But this figure also includes the Dussindale walk-in centre and Cromer minor injuries unit, which improves the percentage from the N&N alone.

Hospital spokesman Andrew Stronach said: "Since March we have been achieving the A&E target. The suggestion that patients are admitted simply to meet the target is not correct. Only after a range of tests such as blood tests, scans or x-rays have been done, can a decision be made to admit or not. That process of clinical investigation does often take a couple of hours and will mean admissions tend to happen towards the end of the four-hour period."

The board meeting of NHS East of England last month was told that after missing the target last year, the N&N "has made excellent progress and is now consistently achieving a high level of performance".