Six leading active travel organisations claimed the Prime Minister will “make the roads worse” if he goes ahead with the move.

Several newspapers reported that a Plan for Motorists will be unveiled at the upcoming Tory conference in Manchester.

This will reportedly include limiting the ability of local authorities to impose new 20mph zones, restricting the number of hours a day cars are banned from bus lanes, and scaling back low-traffic neighbourhoods (LTNs).

Rishi Sunak is expected to unveil motorist-friendly policies during Conservative Party conference in the next few days.

The Guardian reported that the plan also involves reducing the ability of councils to impose fines for traffic infractions such as the misuse of yellow box junctions.

In a joint statement, the chief executives of walking and cycling organisations Bikeability Trust, British Cycling, Cycling UK, Living Streets, Ramblers and Sustrans said: “When ministers could be promoting public transport, cycling and walking as cheap sustainable options in a cost-of-living and climate crisis, they’re entrenching congestion and reliance on driving for short, local journeys.

“When the Government could respect people’s freedom to choose how they travel, it’s removing the alternatives.

“This is a plan that looks no further than one way of travelling and will make the roads worse for those occasions when people do need to drive.”

Earlier this month, Wales became the first country in the UK to drop the default speed limit from 30mph to 20mph for restricted roads.

This came after Wales scrapped all major road building projects due to environmental concerns.

On Thursday, Mr Sunak told ITV Cymru Wales: “I think imposing a blanket 20 mile-an-hour speed limit on areas is absolutely not right. It doesn’t reflect people’s priorities.

“People are dependent on their cars for their day-to-day journeys and these kind of blanket bans aren’t the right, proportionate approach.

“But also it comes on top of this other policy not to build any new roads as well.

“You take these things together, it seems like an attack on motorists and that’s rightly received the opposition that it deserves.”

The Prime Minister has pledged to crack down on “anti-motorist” policies and last week delayed the ban on the sale of new conventionally fuelled cars and vans from 2030 to 2035.

Nicholas Lyes, director of policy at the road safety charity IAM RoadSmart, said 20mph zones “have a role to play” but the “proliferation of blanket limits without physical changes to road layouts means compliance is often poor”.

Local authorities are “usually best placed” to decide the location of the zones but there “is an argument” to strengthen guidance on how that happens, he added.

Rishi Sunak accused of 'making roads worse' if he blocks 20mph zones