Motorists should be allowed to turn left even when the traffic lights are red, a Conservative party review group has proposed.

The plans – which are not yet official Tory policy – are aimed at cutting congestion, which the economic competitiveness policy group argues is holding British business back.

Led by former Conservative minister John Redwood, the group has also proposed removing cycle lanes where they are sandwiched between busy traffic lanes. Instead, cyclists would be granted space to ride on pavements, provided there was enough room.

Taxis, motorbikes and electronically powered vehicles would be allowed into bus lanes, and these lanes would be open to all vehicles outside peak hours.

Councils would also be encouraged to widen junctions, separating traffic going in different directions, and create two lanes around large roundabouts where possible.

In addition, the policy group calls for a review of speed limits to see whether they could be made more effective – for example, during the school run, cars should be limited to 20mph outside schools, but should be able to speed up at any other time.

Mr Redwood said the ideas represented a “commonsense” approach to tackling increasing congestion, as well as making Britain’s roads safer and more environmentally friendly.

However, many of the proposals have been met with scepticism, and the RAC Foundation questioned in particular the plans to allow vehicles to turn left at a red light, saying they could be very dangerous in a big city such as London.

Liberal Democrat transport spokesman Alistair Carmichael also laid into the idea, saying: “On planet Redwood, the lights are always green.

“If the Tories are serious about tackling congestion they should embrace road-user pricing schemes, not recycling failed gimmicks. This idea could conceivably worsen congestion as one can only imagine the chaos it would cause.”

But Mr Redwood told Today: “The rule would be that it would be the same as a Stop sign and that if the road you wanted to turn onto was being used by anyone else, pedestrian or cyclist or van or bus, they took priority.

“You would only be allowed to proceed if the road was completely empty and safe to do so and you would obviously still have to stop at the traffic lights so you would be going at a very slow speed if you decided it was safe to move off.”

Transport campaigners Brake welcomed the proposals for 20mph outside schools, but policy director Cathy Keeler warned other measures “would sacrifice the safety of pedestrians and cyclists for the sake of saving a few minutes of journey times”.

However, Mr Redwood disputed this, saying: “We’re saying that cyclists and pedestrians are very important and we want them to have better provision than they have at the moment.”