The head of Norfolk's biggest hospital said she was happy to be classed as failing by the health regulator after making a move to address a backlog of patients waiting more than 18 weeks for an operation.

The chief executive of the Norfolk and Norwich University Hospital said the NHS trust had failed a key target in May and June of carrying out 90pc of elective surgeries within 18 weeks.

However, Anna Dugdale said the target failure had been worth it after the hospital slashed the number of patients waiting more than 18 weeks for non-emergency surgery by moving those that have been waiting longest to the front of the queue.

As a result, the number of patients waiting more than 18 weeks for elective surgery has reduced from 533 from last May to an all time low of 185.

However, Mrs Dugdale, who has been chief executive at the NNUH for five years, said the move had put her position and the board under extra scrutiny from health regulator Monitor after the trust failed to hit the 18 week target for the last two months.

The chief executive said the move to prioritise those that had been waiting the longest had received approval from members of the board, foundation trust governors, and local Clinical Commissioning Groups (CCG) had waved their powers to fine the hospital trust for failing to hit the target.

Mrs Dugdale said the decision was made in April following a period where the hospital was under intense pressure from a high number of emergency admissions, which resulted in the cancellation of hundreds of elective surgeries.

'We have made a decision that it is not right to not be treating the longest waiting patients first, which flies in the face of the 90pc target. It is the right thing to do and it is the right thing to do for patients and I passionately believe that. It is common sense.'

'The consequences of doing the right thing is that technically we should be fined for breaching our contract with the CCGs and have fallen foul of Monitor's compliance regime. Monitor measures us every month and quarterly and to the end of June, they will have us down as failing,' she said.

The NNUH currently has more than 5,000 patients on the waiting list that have been referred by their GP for surgery. Mrs Dugdale added that it would take a couple of months to clear the backlog of patients waiting more than 18 weeks and she hoped other hospitals would follow suit.

'This is a remarkable achievement, even more so given the challenges presented by a huge surge in emergency admissions between mid-February and mid-April. We have never before had less than 300 people waiting over 18 weeks so this is an enormous milestone for us, but we are not complacent.' 'Waiting for treatment can be a worrying time for patients and we intend to build on this achievement and bring these numbers down even further so that our patients receive the best quality treatment as quickly as possible,' she said.

The NNUH carries out around 150 elective surgeries a day. Mrs Dugdale added that the hospital had hit the 90pc target in 2012/13. However, performance slipped to 88pc in May and in some specialities, the number of patients being treated within 18 weeks had gone down to 50pc, she said. Jonathon Fagge, chief executive of the Norwich CCG, said: 'All of us want to see patients treated sooner, so we are very pleased to see the number of patients waiting more than 18 weeks at the Norfolk and Norwich University Hospital fall so significantly. It is entirely right that those waiting the longest time receive their treatment first.'

The 18 week target does not include patients with urgent conditions and cancer.

The James Paget University Hospital in Gorleston is currently operating on 90.4pc of patients within the 18 week limit.

A total of 93.1pc of patients at the Queen Elizabeth Hospital in King's Lynn were treated within the 18 week target in 2012/13.

And at the West Suffolk Hospital in Bury St Edmunds, 99.97pc were operated on within 18 weeks in 2012/13.