Bold draft proposals to reduce speed limits in the capital’s Square Mile were put forward by the City of London corporation as part of its long-term strategy to improve road safety and cut pollution.

The corporation, which governs the City of London, suggested an authority-wide 15mph restriction could save lives by encouraging motorists to be more considerate behind the wheel.

Last year, 54 people were killed or seriously injured on City streets.

But despite imposing lower speed limits of 20mph, record numbers of workers on London’s streets has meant the number of overall deaths has not decreased.

The proposed plan to reduce speeds by another five mph has been slammed by road experts, who are sceptical that the plans would have any gain.

An AA spokesperson said: “What happens with 20mph zones is they bring the vast majority of drivers below 30mph.

"The majority of drivers drive at 25mph in these areas and we would get the same with 15mph zones.

"London traffic moves no faster than a horse and cart anyway and it won't help with pollution as you have more cars stopping and starting all the time.”

Any 15mph restriction, thought to be the first of its kind on city centre roads, would need to be approved by the Department for Transport.

The corporation hopes the restriction will be in place by 2022 in a bid to curtail the number of deaths and serious injuries to cyclists in the Square Mile.

Motoring group IAM RoadSmart is against blanket reductions to 20mph, with spokesman Rodney Kumar casting doubt over the proposed 15mph limits making any improvements to roads.

He said: “We don’t see a proposed reduction to 15mph having the desired effect in terms of congestion, pollution or road safety.”

The proposed drop from 20mph to 15mph by 2022 is one of a series of measures designed to reduce pollution, further reduce the number of accidents and cope with the extra numbers of people coming into the City as more new buildings go up.

If accepted, the plans would see ‘pedestrian priority’ zones introduced which would see cars, vans, taxis, and buses banned from using certain routes.