In a response to Khan’s letter, which said that pledging further guarantees of the public money he is responsible for would expose London taxpayers to "too much additional financial risk", chairman of the Garden Bridge Trust Lord Mervyn Davies said the board was still confident the trust could raise the money needed for the project to proceed. He said it was sad that Khan had a different view of the project than his predecessor, Boris Johnson.
Lord Davies said: "We received the Mayor's letter with great regret today. We will study the contents of the letter in detail before responding formally.
"The Garden Bridge Trust was set up at the request of Transport for London and the Department of Transport to deliver the project which had received public money.
"We have had enormous support from our funders and are very confident we can raise the remaining funds required. But sadly the Mayor of London has taken a different decision to those in place when the project started."
The project could still go ahead if enough funds are raised but it is a condition of the bridge's planning permissions that future operational and maintenance costs be underwritten by the Mayor of London, if the trust is unable to raise enough money from private backers, commmercial activities and fundraising. That condition could be amended but current planning permission expires in December, leaving limited time for the trust to secure the funds needed to give the bridge a secure future.