Labour's London mayoral candidate Sadiq Khan has pledged to scrap Boris Johnson's controversial "garden bridge" across the Thames, insisting that it "no longer represents value for money"

The Treasury and City Hall have pledged £60 million of public money towards the scheme championed by Joanna Lumley.

However Khan, who is the current bookies favourite to replace Johnson, says he will use the money to fund the pedestrianisation of London's Oxford Street instead.

“In principle I love the idea of the Garden Bridge, but what we were sold is a long way from the reality we now face," he said today.

"It has become another of Boris Johnson’s white elephant projects – like the Cable Car which is used by few at the cost of millions of pounds.

“I believe it no longer represents value for money. This was supposed to be an entirely privately funded project... but the overall cost has tripled, and £60 million is being paid for out of the public purse, with a possible maintenance cost of £3.5 million a year – for a bridge which will often be closed to the public for private events and won’t be open overnight."

City Hall say the bridge will be closed for corporate events up to twelve times a year. Cyclists will also be banned from using the bridge as part of a series of strict rules over its use.

Johnson is a strong supporter of the bridge. A freedom of information request by the Architects' journal earlier this year revealed that Lumley had heavily lobbied Johnson who is a long-time acquaintance.

The scheme remains controversial with local people and repeated questions have been raised about the procurement process behind appointing Thomas Heatherwick to design it.

The GLA this month published 30 rules governing behaviour on the planned bridge, including restrictions on the playing of "any game or...any form fo sport or exercise," as well as the delivery of "any speech or address".

Absolutely no fun or games to be allowed on Boris's new garden bridge via @se1 pic.twitter.com/KkclIzyz0f — Adam Bienkov (@AdamBienkov) September 22, 2015

Khan's leading Conservative rival Zac Goldmsith has pledged his support for the bridge saying that it would be a "beautiful" addition to London's architecture.