An environmentally-friendly car that runs on compressed air could be on sale within a year, according to French engineer and inventor Guy Negre.

The OneCAT, a five-seater vehicle with a glass fibre body, weighs 350kg and could cost just over £2,500.

The vehicle will be powered by compressed air stored in carbon-fibre tanks built into the chassis. The tanks can be filled with air from a compressor in three minutes, or alternatively, can be plugged into the mains for four hours and an on-board compressor will do the job.

For long journeys the compressed air driving the pistons can be boosted by a fuel burner which heats the air so it expands and increases the pressure on the pistons. The burner will use all kinds of liquid fuel.

Negre has been promising for more than a decade to be on the verge of a breakthrough, however having recently secured backing from Indian conglomerate Tata to put the finishing touches to the engine, independent observers are more convinced it could come through this time.