A borrowed helicopter providing Oxfordshire's life-saving air ambulance service is out of action because it was not considered to be of the same standard as the original aircraft.

Talks are set to get under way with contractors over the Squirrel helicopter, a short-term replacement for the state-of-the art Agusta, which crash-landed on June 17. The Royal Berkshire Ambulance Service, which runs the service in partnership with Oxford Ambulance Trust, chartered the replacement aircraft when the original one was forced to make an emergency landing near Wokingham after a sudden power loss.

The pilot escaped uninjured and two medical staff suffered minor injuries. All are now back at work.

But delays have meant the Agusta may not return to the skies for two more months. Meanwhile the Squirrel, which carries fewer patients, has also been out of action since Sunday, it has emerged.

Nigel Webb, chief executive of the National Air Association of Air Ambulance Services was due to meet with contractors today to discuss the problem and try to get a suitable replacement.

He said: The Squirrel is much smaller. It can only take one patient and that impedes medical attention.