MERCEDES Benz could pave the way for a Cotswold inventor's road safety device becoming an international life saver.

John Birtles, who lives in Hatherop, near Cirencester, claims his simple brake warning system for motor vehicles could prevent 50,000 accidents a year.

But, despite wide support from road safety groups and car giants such as Saab and Volvo, the Department of Transport (DET)- now the Department for the Environment, Transport and the Regions - claims it is unreliable.

Mr Birtles has hit back angrily and says various firms are "sitting on the fence" waiting to see if someone will finally take the invention on board. And, following a productive meeting with Mercedes Benz officials on Tuesday, he is optimistic for the future.

He said: "If Mercedes take it up in any form, the whole world will follow - there won't be a single manufacturer who won't.

"The technology is based on infra-red, which has been around for years. This doesn't fail - it's totally reliable."

Rearguard involves fitting an extra set of rear warning lights which alert motorists that the driver in front is about to brake.

The lights are illuminated when an infra-red sensor detects that the driver's foot is hovering over the brake pedal.

The lights remain on until the driver starts to accelerate again.

The system, which costs just £5 to install, has also won the support of the Spinal Injuries Association, the police, Safer City - a Government-backed road safety project in Gloucester - and the Road Safety Liaison Group.

Mr Birtles added: "The outstanding evidence is that Rearguard will be highly effective."

* After developing the system in 1996, Mr Birtles contacted the DET. He says, initially, Government officials offered "excellent" support but then suddenly changed their minds.

Officials from the department tested the machine themselves.