Last week it was a case of Thunderbirds are go for Britain’s answer to Disneyland, as ITV struck a deal for the famous kids’ show to be turned into an attraction at a £5bn theme park. But the backers of the London Resort, planned for a peninsula in north Kent, are struggling with film and TV partners walking away and increasing disillusioned locals.

In signing the ITV deal Steve Norris, the former transport minister who chairs the park’s developer London Resort Company Holdings, promised the broadcaster it was going on an “epic journey”. It already has been.

Unveiled in the post-Olympic euphoria of late 2012, the plan to create a theme park three times larger than any in the UK, located in the south-east of England to complete the cross channel rivalry with Disneyland Paris, caught the imagination. A tie-up with Hollywood studio Paramount Pictures led to concept images of rides and attractions based on mega-hits such as Mission: Impossible, Star Trek and even The Italian Job. The park, financed by Kuwait’s Al-Humaidi family, who own Ebbsfleet United, would open in 2019, the developers said.

The London Resort map The London Resort map

Fast-forward seven years and Paramount Pictures has disappeared, pulling out in 2017; so too Aardman Animations, the studio behind Wallace & Gromit, Chicken Run and Shaun the Sheep, which allowed a licensing deal for attractions based on its characters to lapse. The Guardian has learned that the British Film Institute, brought on as “cultural advisers” in 2015, is also no longer involved. Final plans are still yet to be submitted to the government and the opening date has been pushed back five times to 2024.

“There is considerable cynicism about the project now,” says Prof Richard Scase of Kent Business School. “People have been hearing about this scheme for the last seven years. Like with the HS2 rail development it creates a planning blight affecting the value of properties; are roads being put in people’s back yards, will houses be compulsorily purchased, what about congestion? The initial enthusiasm of 2012 has evaporated. Theme parks are risky, is it really going to be an asset to the local community. The whole thing is shrouded in mystery and uncertainty.”

On paper, the plans for the venture seemed impressive. It will be developed on 535 acres, the size of 136 Wembley stadiums, on a former landfill site on the Swanscombe peninsula, jutting into the River Thames near the Dartford crossing. The plan is for 50 attractions and rides including Europe’s largest indoor waterpark, with more than 3,500 hotel rooms and attracting 15 million visitors a year. The developers quickly hired the London Olympics commercial chief to drum up more media partners and create more themed attractions and rides.

The locals initially embraced the plan – nine Gravesham district council bosses flew out to the US to research Florida’s theme parks. Even the discovery of a colony of rare jumping spiders in 2013 (they liked the alkaline land created by the cement kiln dust from the former cement works at the site) did not become an obstacle, with the company saying it would create a 27-acre wetland wildlife park at the attraction. A year later, the government designated the development the first major leisure scheme to be a project of national significance, allowing its plans to bypass local laws and go straight to the secretary of state for approval.

By 2015 the project looked in great shape with the BBC signed up, opening the possibility of attractions based on shows from Doctor Who to Top Gear; so too Aardman and the BFI. Since then, things have not gone well. The plans for a standalone waterpark have disappeared; the developers now say the cost has risen from £2bn to £5bn. Construction is earmarked to begin in 2021 and LRCH remains optimistic.

“The London Resort will be one of the top 10 global resorts in the world,” said a spokesman for LRCH. “We will be competing directly with Disneyland Paris, and with Disney World and Universal Studios in Orlando. A project of this scale naturally takes time to get right. A lot of work has been going on behind the scenes [and] there is now significant momentum behind the project as we build up towards the planning application.”

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Abdulla Al-Humaidi, whose family own Kuwaiti European Holdings, which is financing the project, has been more frank about the state of affairs. Last year, he took over the role of chief executive atLCRH, saying: “[I] very much regret that more progress has not been made.”

Last month, Al-Humaidi, chairman and owner of Ebbsfleet United, told fans he would continue to fund the loss-making club but at a “more manageable level”, cutting out expenses such as trips to Portugal and player relocation costs.

“Too much money has been spent, too much to measure against progress in the past few years,” he said. He could easily be talking about the rollercoaster ride of his significantly bigger investment just a few miles down the road.