London Mayor Boris Johnson has appointed Transport for London to explore construction of a 22-mile underground ring road to ease traffic congestion in the capital city.

The Inner Orbital Tunnel is the brainchild of the roads task force that was created by the Mayor in 2012 and would require an estimated investment of £30bn.

It involves construction of two new crossings beneath River Thames and will connect several key overland roads, including the A40 in the west to the A12 in the east, as well as the A1 in the north and the A2 in the south.

"This is not about creating a motorway through the centre of London."

The project will take thousands of vehicles off the surface roads, resulting in the reduction of both congestion and pollution.

The proposed route is expected to link Camden, Highbury, Whitechapel, Elephant and Castle, Oval, Battersea Park and Earl’s Court.

Speaking to Evening Standard newspaper, Johnson said that there are arguments in favour and against the idea.

Deputy mayor for transport Isabel Dedring told the publication that the Greater London Authority is in the very early stages of exploring the route’s potential.

"Cities such as Paris, Oslo and Boston have undertaken these kinds of ambitious projects and have seen dramatic results," Dedring said.

"This is not about creating a motorway through the centre of London. It is about freeing up capacity on the city surface, improving air quality and reclaiming space for public parks, pedestrians and cyclists."