The £175 million bridge, designed by Thomas Hetherwick with engineering and hard landscaping by Arup and planting design and soft landscaping by Dan Pearson, has come under increasing scrutiny as first Lambeth and then Westminster councils decided to grant it planning permission this month.
Several commentators expressed concern about the cost, the impact on views and on the streetscape on either side and its long-term maintenance plan. A petition on the change.org website against the current plans started by Thames Central Open Space has attracted 1,875 signatures.
St Paul’s Cathedral’s surveyor to the fabric, Oliver Caroe, called for the decision on the project to be deferred in a letter to Westminster council ahead of its decision on 2 December, saying cathedral bosses had "significant misgivings" about the scheme and had not been consulted.
Caroe said it would have an "irreversible impact" on views of the cathedral and said no decision should be made without "a full consideration of and debate over the significant adverse impacts on the views and setting of St Paul's Cathedral which have been identified.
"At present the voice of the cathedral and that of other concerned specialists has not been fully heard."
He argued that without further analysis by experts and bearing in mind that views are protected under The St Paul's Heights and The London View Management Framework legislation the councillors should turn the current application down.
"The significance and value of these views does not yet appear to have been fully evaluated and understood. Once harmed these views will not be recovered," he said.
The letter came ahead of the council’s planning meeting which granted planning permission for the scheme and was also sent to Boris Johnson and others.
Others have expressed concerns about interrupted views to St Paul’s Cathedral, including the City of London Corporation, which said in its response that the bridge would have "a major impact" on views of St Paul's and the City from the south bank and Waterloo Bridge.
It goes on to say that these impacts should be balanced against the quality of new views being created.
The report put before planning councillors on 2 December said that it was "inevitable that there will be a significant impact on important views" and goes on to say that from the middle of the bridge the views of St Paul's are little affected but from either end the cathedral's dome would be partially obscured.
But speaking at the meeting, chairman of the planning comittee Robert Davis, deputy leader of Westminster City Council, said that while he understood concerns about potential loss of views there "is no doubting that this bridge will bring substantial and significant benefits to London.
"This is something that is iconic and absolutely unique, and will be recognised right across the world."If Johnson gives the go-ahead the charity in charge of the project, The Garden Bridge Trust, estimates work could start in 2016.
Out of 292 replies to the planning consultation, 279 letters were in support of the Garden Bridge
English Heritage, The Mayor of London, Transport for London, Somerset House and Kew Gardens all support the proposals, which would see 270 trees in 45 different species planted and see approximately seven million visitors per year.
A Garden Bridge Trust spokesman said that the trust had carried out extensive consultation before submitting the planning application to Lambeth and Westminster councils and there was no statutory obligation to consult with St Paul’s specifically.
"Our consultation included public meetings, drop-in sessions and speaking to community and local interest groups. We produced over 45 photomontages to demonstrate the effects of the footbridge as part of the environmental statement (ES) which assessed the impact on a number of views.
"Viewpoints were identified using the London View Management Framework (LVMF) 2012, and in consultation Westminster and Lambeth councils and English Heritage. They include analysis of the scheme at year 1 and year 25, as well as summer and winter and day time and night time.
"We believe the Garden Bridge will protect existing views along the River Thames, enhance others and provide new beautiful views up and down the river that are currently not possible. There is huge support for the Garden Bridge and we are keen to work with people over the coming months to make the most of the opportunities it has to offer, to create a footbridge which become a celebrated part of London's landscape."