The mile is set to be dropped in favour of the kilometre, once a target of 50 per cent of motorists have been taught the new measurement, predicted to be in between five and ten years time.

It is expected that the change will be counted down to from after the general election, prompting calls from the UK Independence party and the British Weights and Measures Association for drivers to protest to keep the mile.

However, transport officials have denied that such changes are planned.