The crisis that developed at Eden in recent years has prompted three people closely connected with the project to contact Third Sector and express dismay at the way it has been managed. They asked to remain anonymous.
One points out that similar attractions, such as the Royal Botanic Gardens, Kew, have successfully found new revenue streams, but Eden has remained heavily reliant on paying visitors, income from its shops and restaurants, and grants. "Whether it's salvageable now, I don't know," says that informant.
Other criticisms are that the project has not put aside enough money to repair and replace its biome structures and equipment, and that there were too many highly paid senior staff while many front-line staff were on zero-hours contracts and paid close to the minimum wage.
Peter Stewart (right), joint interim executive director, says that, with hindsight, cuts should have been made sooner, and the project would have liked more diversification initiatives to be successful. Otherwise, he and David Harland, the other joint interim executive director, dispute all the criticisms and assert that Eden is now on course to recover.
Harland says the project has been spending between £1.5m and £2m on maintenance in recent years, which he says is more than enough to preserve the fabric. "The steel structures have a life of 50 years and the plastic panels have a lifespan of 25 years," he says. "We also know that they won't all go wrong at the same time. The thinking that the structures are going to fall down because we're not maintaining them is categorically wrong."
The latest annual report of the Eden Trust says: "In the long term, the trust is aware of the need to build a sinking fund to provide for the ultimate replacement of the biomes, thus ensuring that the remarkable Eden experience is secured for future generations."
Harland (right) also disputes that the project was too management-heavy and says the recent cut from 14 to six in the number of senior staff paid more than £50,000 has been made because fewer people are needed to manage a project with fewer staff and visitors. "When your numbers are low, you need less management resource," he says. "If we're being candid, management is where the savings are. I don't think it necessarily indicates that we had too many managers before - it reflects more the reality of where we're at now."
He declines to say how much senior staff, including Smit and Coley, were paid: "The way we report salaries is kept under review by the trust, and this element will be reviewed again by the trust for the 2014 accounts.
"At present it is our policy not to disclose the pay rates of named individuals. The highest-paid person currently receives a salary of £125,000 a year."
The project's accounts for the year 2012/13, however, say the highest-paid person received £157,372.
Harland says some front-line staff are paid £6.44 an hour - just above the national minimum wage of £6.31. He says the project would like to pay more, but is not in a position to do so yet. Ninety-one of more than 500 people who work at Eden are on zero-hours contracts, but Harland says "it has not been an enforced measure - it actually suits them to do that seasonally".
Smit and Coley: Eden's 'prominent people'
Sir Tim Smit (right) worked as a composer and producer in rock music and opera before moving to Cornwall in 1987, where he and his former wife Candy restored the visitor attraction the Lost Gardens of Heligan. In 1995, he began to work on the Eden Project, which opened in 2001.
Gaynor Coley joined the project in 1997 as finance director and in 2001 was promoted to managing director before eventually becoming joint chief executive with Smit. In 2003 the Daily Mail reported they were in a relationship, something that was common knowledge among Eden staff, according to Third Sector's sources.
Third Sector asked Harland and Stewart to comment on the contention of its informants that Smit was a creative man of ideas rather than a manager and that he and his partner Coley bore some responsibility for Eden's current difficulties.
Harland says: "I don't think we want to comment. We couldn't accept that."
David Rowe, Eden's media relations officer, says: "You have named two prominent people in our organisation. We don't accept that at all." Stewart adds: "Eden has seen a transformation. A £140m investment has brought £1.3bn of economic benefit and jobs to a hard-pressed part of the country.
"Tim would say he didn't build Eden - he had the ability to galvanise people. He would admit openly to things he can't do."