Culture chiefs have warned the city faces being left with a run-down Ross Bandstand which is “no longer fit for purpose” and a garden which effectively excludes “untold numbers” of residents and visitors due to poor access from Princes Street.
They insist they will never “sell off” any part of West Princes Street Gardens, which developer Norman Springford hoped to transform, or agree corporate sponsorship deals which “impact negatively” on the park.
The businessman, who set up the Ross Development Trust to pursue his plans, has severed his links with the project, admitting that questions over his motives, and claims the gardens would be commercialised or privatised, had become “a distraction.”
However he has insisted he will honour the £5 million he first pledged five years ago to get the redevelopment project off the ground and that stepping back now will “give it the best chance of being realised.”
Culture chief Donald Wilson described public-private partnership as "an outstanding opportunity to invest in and enhance one of the most stunning settings in Scotland.”
However, the Cockburn Association heritage watchdog said Mr Springford’s ambitions for the project “no longer looks the way to go” and said his departure may mark the start of a “new chapter”.
The group is demanding the cancellation of open-air pop and rock concerts in the gardens and a ban on Hogmanay festivities
Mr Springford, former owner of the Edinburgh Playhouse, stood down as chair of the Quaich Project a week after details of a secret “debenture scheme” to help pay for the redevelopment were leaked.
Fundraising brochures for the venture have promised big businesses and individual donors access to high-profile celebrities, tickets for major concerts, and exclusive drinks patties and dinners in a converted cottage in the gardens.
The brochures, which were not approved by a council committee, suggested corporate backers will be able to link their brands to everything from new pathways and seating in the gardens to a 5000-capacity amphitheatre to replace the Ross Bandstand.
Councillors have insisted they were kept in the dark over the details of the fundraising campaign, which has been backed by stars like actors Iain Glen and Alan Cumming, and the singer KT Tunstall.
But Mr Wilson insisted that if the council was able to proceed with the full range of improvements planned under the Quaich Project vision, “West Princes Street Gardens would again be transformed into a space for everyone to enjoy in the heart of the city.”
He said: “Princes Street Gardens is one of our greatest green assets and quite rightly holds a special place in the hearts of residents and visitors.
"Our ambition is for this to be a place for people of all ages to enjoy now and in the future. It will remain a publicly-owned and managed treasure for generations to come.
“However, if you’re a wheelchair user or pushing a pram, access is currently extremely difficult from most entrances, meaning untold numbers of residents and visitors are effectively excluded from spending time in this magnificent green space.
"The bandstand is no longer fit for purpose – there is too much concrete and not enough greenery. Community use has dramatically reduced from its peak in the 1950s-60s.
"Rather than continue with patchwork improvements to the gardens on our own, we welcome the trust’s support and funding approach, which allows us to set our sights much higher.
"It’s important to stress that while the trust leads on delivering the project and sourcing funding, executive control and governance remain with the council.
“Edinburgh has long benefited from the philanthropy of generous benefactors – the Ross Bandstand and nearby Usher Hall being prime examples of this – and the trust’s philanthropic giving fundraising strategy is looking to harness these benefits to continue this fine tradition.
"Should it reach its fundraising target, West Princes Street Gardens would again be transformed into a space for everyone to enjoy in the heart of the city.”
Cllr Wilson insisted it had always been intended for private finance to help pay for the gardens to be redeveloped under the agreement struck with Mr Springford, but insisted that any "significant" corporate donations would have to be given the final approval by councillors.
He added: "To be absolutely clear, there are no proposals to sell off any part of the gardens or for sponsorship deals which impact negatively on Common Good Land, and there never will be.
"The Quaich Project is providing us with an outstanding opportunity to invest in and enhance one of the most stunning settings in Scotland. We look forward to continuing our support for this – and the huge benefits it could bring to the people of Edinburgh and beyond."
However writing in The Scotsman today, Cockburn Association chair Cliff Hague said the council and the “promoters” of the Quaich Project had “boxed themselves in”.
He added: “By aspiring to make the gardens “the focal point for a unified city-wide entertainment and exhibition offer” they are courting unnecessary controversy.
“A less expensive, more modest approach could command widespread support. Making ‘nature’ the unambiguous top priority would be the best fit for the climate emergency, and is what people most value about this gem in the World Heritage Site.
"Reimagine the play area and the shelters, and find ways to improve disabled access, particularly at the west and east entrances where most people enter or leave.
"Make the existing bandstand and seating fit for the kind of small community-based events which featured prominently in the public consultation.
“It is the expensive and intrusive ‘big ticket’ items in the current proposals – the welcome centre/corporate entertainment building, the new stage, and bridge over the railway to enable larger articulated vehicles to access the gardens – that propel the marketing of naming rights and exclusive corporate events.
"The £5 million the council has committed to providing could go a long way to delivering the smaller upgrades. If more is needed, look to borrowing, real philanthropy or crowdfunding, but not corporate branding."
Mr Hague said he would be in favour of cancelling major outdoor events in Princes Street Gardens, such as the summer pop and rock shows that have been revived in recent years, and the focal point of the city's Hogmanay celebrations.
He added: " Dropping these would be an immediate step to delivering the aim in the new Edinburgh tourism strategy to manage tourism and make Edinburgh 'an exemplar in achieving environmentally sustainable urban tourism.'
"If the city and the industry are serious about this, they have to say no to some things. Events designed to attract more tourists at precisely the times when the city is already most crowded should top that list."