Converting hard shoulders to permanent driving lanes is dangerous and should be scrapped, a Commons committee has said.

The government wants to turn hundreds of miles of hard shoulder in England into normal driving lanes, a process known as ‘all-lane running.’ The idea is to increase capacity without the cost of paving new lanes.

The Department for Transport claims that ‘all-lane running’ has been designed to be as safe as a normal motorway, but the Transport Select Committee says the “dramatic change” would be dangerous.

Sections of the M25, M1 and M6 already use the scheme, and other motorways look set to adopt ‘all-lane running,’ including the M3 and M23.

The government says it is a natural progression from ‘smart motorways,’ which open the hard shoulder when traffic is heavy, often with a reduced speed limit. The new system would see the hard shoulder opened permanently, and some motoring groups have joined the Committee in saying that’s not safe.

The RAC and AA are among those unconvinced by the new plans, claiming emergency run-off areas become far less common. Currently, the hard shoulder offers a safe haven to those experiencing a problem that requires them to stop, and removing that puts people in danger, they say.

There are also concerns that drivers could become confused about which sections of hard shoulder are open and which are not.

Edmund King, president of the AA, said: "Breaking down on a motorway in a live running lane is every driver's worst fear.

"Whilst we need to increase capacity and reduce congestion we must ensure that we are not cutting corners which compromise safety just to reduce costs."

A Department for Transport spokesman said: "We will be considering all the Transport Select Committee's findings carefully and responding shortly.”