Ambulance services in Hertfordshire have been slammed in an official report, prompting bosses to insist it is unfair.

The East of England Ambulance Service NHS Trust has been marked "weak" both for quality of service and use of resources in the Healthcare Commission’s annual healthcheck for 2007/8, published today.

Chief executive Hayden Newton said: "The scores, while disappointing, in no way reflect on the quality of care provided by staff across the region.

“Our quality of services score results solely from errors in the response performance data submitted to the Healthcare Commission. "

He said it had emerged that on a small number of occasions, arrival times had been logged incorrectly, leading to a mandatory "weak" rating.

He added: "This does not reflect on the care we provide to the public in the east of England and I would like to thank all of our staff for their continued commitment to providing the best possible service to patients.

”The Trust has since strengthened its auditing processes in control rooms.

"The 'use of resources' score relates to the Trust’s financial management and internal governance last year, since when significant changes and improvements have been made."

He added that ambulance response times had greatly improved, with more than 80 per cent of life-threatening incidents attended within eight minutes .