Backed by actress Joanna Lumley, the £150m bridge is being majority funded by private, charitable and commercial donors but is also set to receive £60m of public funds pledged by former mayor Boris Johnson and the Department for Transport.
Mr Johnson also committed Transport for London to underwrite the bridge’s maintenance costs in perpetuity should its sponsoring Trust be unable to raise enough money from corporate lets and hospitality to meet its bills.
Last September Mr Khan described the bridge as “another of Boris Johnson’s white elephant projects” and suggested he would pull City Hall’s support for the project and use the cash earmarked for it “in a way which is more beneficial to London’s economy”.
However two months later the then Labour candidate for mayor claimed credit for a deal which will see £20m of TfL’s pledged £30m “treated as a loan” rather than a grant.
Today Mr Khan’s office confirmed the new mayor was now backing the project in return for guarantees from the Garden Bridge Trust to increase public access.
As a result of a deal struck between the Trust and City Hall, the bridge will be closed for fewer days each year to host private fundraising events and will only close for those parts of the day needed to host the event, rather than all day as was originally planned.
In addition the Trust has agreed to supply seeds and plants grown on the Garden Bridge to London’s parks.
Mayor Khan said: “The Garden Bridge could rival New York’s High Line. But it must be a genuinely public and open space for all Londoners, rather than a closed and private space.
“I expect the Garden Bridge Trust to ensure that the Bridge be closed fewer days each year for private fundraising events and fewer hours when they do. I also want a guarantee that an ongoing programme of visits will be laid on for local school children.
“The Trust must also look to build a strong working relationship with parks from all over our city, so that seeds and plants grown on the Garden Bridge can then be replanted in parks across the capital – ensuring it has a positive benefit for all Londoners.”
Critics of the bridge and some parties on the London Assembly have previously raised concerns about the procurement process followed by TfL when awarding initial contracts for the bridge.
In March an Assembly report claimed there were “a series of procedural errors in the procurement process” and questioned whether Mr Johnson had been “upfront” about his dealings with designers Heatherwick Studios.
AMs had also criticised TfL’s refusal to publish the full businesses case for the bridge.
Mr Khan has now reversed that position and asked TfL to publish both the business plan and a list of its funders.
Liberal Democrat London Assembly Member, Caroline Pidgeon, has described the mayor’s backing for the project as “highly disappointing”.
She commented: “Instead of tinkering with minor changes from the Garden Bridge Trust the Mayor should be seeking to recoup every penny of Transport for London funding that has been allocated to this highly controversial project.
“The Mayor should also be refusing to underwrite the annual maintenance costs of this project.
“There are numerous transport projects in London that desperately need public funding and are a far higher priority than this vanity project from the previous Mayor.”
Green party AM Caroline Russell added: “The Mayor is talking about cutting back on TfL waste to fund his fares freeze and yet is missing this obvious opportunity to scrap a vanity project and focus funding on things that would deliver genuine benefit to Londoners.
“There’s no case for the Garden Bridge on transport, horticulture or tourism grounds. Asking for fewer closures for private events is just not good enough.
“The Garden Bridge should be scrapped and the Mayor should focus on delivering bridges in East London where people need routes for walking and cycling across the river.”
