AMBULANCE chiefs have defended the safety record of US ambulances after the latest in a series of crashes.

Paramedic Joel Byers, of the North East Ambulance Service, warned that lives would be lost after he was involved in a third crash in a Chevrolet ambulance.

Mr Byers, 48, suffered whiplash and minor injuries after the brakes and steering apparently failed before his vehicle ploughed into a crash barrier in Chester Road, Sunderland.

Monday's incident led to a call from the public service union, Unison, for urgent safety checks on the Chevrolet ambulances.

Ray McDermott, Unison branch secretary, said: "We have serious concerns about the safety of these vehicles and have voiced and written our concerns to the trust.

"Thankfully, accidents to date have involved vehicles going quite slowly. But what happens when these vehicles fail when going at 60 and 70mph?"

The American-made ambulances have attracted controversy since they were introduced in the former Northumbria ambulance area in 1993, with claims that they have been involved in at least a dozen accidents.

In September 1998, two paramedics were injured after two wheels came off their Chevrolet ambulance.

Since the merger of the Northumbria and County Durham services two years ago, the Chevrolets have been used throughout the region.

Mr Byers, from Newcastle, is already suing ambulance chiefs after suffering whiplash injuries in a similar accident three years ago.

Nine months ago, he said, he had another near-miss when his Chevrolet suddenly lost power.

Monday's accident was similar to a crash in 1998, when the emergency cut-out switch in the cab accidentally activated, leaving the ambulance with no brakes.

Robert Alabaster, spokesman for the North-East Ambulance Service, said he wanted to reassure the public that the Chevrolet ambulances were safe.

"We obviously take safety very seriously. We have increased the frequency of service intervals and replaced the drive belts on these vehicles every 5,000 miles to minimise any problems with them," he said.

The ambulance service was now buying Mercedes vehicles and the number of Chevrolets remaining in service would gradually be reduced, he said.