Health chiefs have warned that they may never eradicate ambulance delays at the Norfolk and Norwich University Hospital, despite a big reduction in patient handover times.

Average handovers have been slashed from 25 minutes in 2012 to just over 15 minutes at the front doors of the Colney hospital following work to increase A&E staffing and capacity.

However, officials from the hospital have warned that a target to have no delays of more than 15 minutes from ambulance arrival to patient transfer was 'unlikely' because of a year-on-year rise in the number of emergency admissions.

Ambulance bosses added that the introduction of a 24/7 hospital ambulance liaison officer (HALO) team at the N&N this winter had speeded up handovers. However, funding for the HALO project ended on March 31.

Members of the Norfolk Health Overview and Scrutiny Committee will quiz commissioners, hospital and ambulance chiefs next week about their ongoing work to reduce ambulance delays.

Councillors are set to hear that the hospital has come a long way since 17 ambulances were queued up outside the N&N on March 6 2013 and when an emergency tent was erected outside A&E as a precaution last Easter Monday.

In a report to councillors, Chris Cobb, director of medicine and emergency care at the N&N, said the introduction of an immediate assessment unit (IAU) and the HALO posts had significantly reduced delays and the hospital had achieved its target of seeing, treating, admitting or discharging 95pc of patients in under four hours this winter.

He added that the hospital was predicted last year to incur fines for ambulance delays of up to £3m in 2013/14. However, fines over the last year for more than 30 and 60 minute waits at A&E were £53,400.

The success in reducing delays comes as ambulance attendances are 15pc higher in 2014, compared with the previous year.

Mr Cobb added: 'Ambulance delays in excess of 60 minutes have been largely eradicated. However, the increase in emergency activity levels at the hospital has added significant challenges at times of unpredictable peaks in attendances.'

'The average time for ambulance handover from October to February is 15.44 minutes. However achieving a 15 minute ambulance turnaround 100pc of the time is unlikely without a significant reduction in attendances/admissions and/or equally significant investment in additional A&E capacity.'

Matt Broad, general manager for the ambulance service in Norfolk, added that a business case had been submitted to the Norwich Clinical Commissioning Group to continue the HALO scheme. He added that the role would continue, but in a reduced format.