The fight to reopen Manston as an airport has been dealt a potentially devastating blow after a report by industry experts concluded it would not be commercially viable.

The report, commissioned by Thanet District Council, makes gloomy reading for both campaigners and the American investment company RiverOak.

The firm is battling to acquire the site from its current owners who want to develop it for homes and businesses.

It reacted angrily to the shock development saying the report was "thin on evidence" and "irrelevant."

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In a statement, the company vowed it would continue its bid to re-open the site as an airport and called on the council to hold off any decisions until it had published its own dossier.

It said: "The report is also extremely thin when it comes to evidence on freight demand. The only ‘forecast’ they rely on is in fact a statement of freight volumes from 2000-2012, when it is widely accepted that there is a considerable and growing level of unsatisfied demand."

The statement added that it had carried out its own interviews about freight demand all of which were positive.

"The results of these will be published in due course. We therefore recommend that Thanet Council waits to see the evidence that forms part of our application before reaching any conclusions on the viability of Manston Airport as a cargo hub."

However, the conclusions of the council's assessment are so bleak about the chances of Manston succeeding as a commercial cargo airport that the Ukip-led council will now formally scrap its intention to include the site as one suitable for aviation use in its local plan.

VIDEO: The plans to re-open Manston as an airport have been scrapped.

Consultants say it would take decades for any investor who took on Manston as a cargo operation to make any money and even then, any chance of success would hinge on there being no increase in aviation capacity in the south east for 50 years - something it describes as a “low probability”.

The report, which the council commissioned in June, spells out in detail just how unlikely it is that Manston could flourish under various scenarios.

It says that if even if there was no aviation expansion elsewhere, the airport would lose money until 2025, require £20m refinancing in 2028 and again in 2029 and investors would not see a return on their money until 2043.

The report suggests that even these forecasts may be over optimistic as it has based them “on a set of assumptions that favour Manston at all times” including what are described as “aggressive cost reductions” and “minimal acquisition costs”.

It points out the market for freight cargo already has significant spare capacity, with operations at Heathrow, East Midlands and Stansted only using half of what is available.

It says that even at its high point, Manston only moved between 25,000 and 30,000 tonnes of freight each year - equivalent to just 1% of the overall market.

“For any operator to achieve these freight movements through Manston, they would have to move from taking 1% of the market to shipping a third of all international freight movements in and out of the UK.”

"Manston has a glorious history but a different future" - Chris Wells, Ukip council leader

The report concludes: “Avia Solutions concludes that airport operations at Manston are very unlikely to be financially viable in the longer term and almost certainly not possible in the period to 2031.”

Ukip council leader Chris Wells said it was the end of the road for Manston as an airport so far as the council was concerned.

He said: “It is with regret that I must accept the solid evidence-based report that tells me what I do not want to hear but must listen to. Manston has a glorious history but a different future.”

He also poured cold water on RiverOak’s plans.

The company was interviewed as part of the study.

He said: “It is the third time RiverOak has failed to sell its plans and has failed to persuade industry specialists of their credibility.”

However, Ukip will face criticism after pledging as part of its election campaign to save Manston.

And Thanet MP Sir Roger Gale, who has championed the reopening of the airport, is unlikely to throw in the towel.

Thanet council appointed consultants earlier this summer to examine whether Manston could have a viable future as an operational airport.

It said it needed to have independent advice about the issue to determine whether it could be included in its Local Plan - the council’s long term development blueprint.

The council also said it needed to satisfy the planning inspector charged with signing off the plan that the council had “robust evidence” an airport could be viable over the lifetime of the plan - which runs until 2031.

Consultants Avia Solutions, who were paid £50,000, were asked to consider if Manston could be a commercial success in the context of the national and international aviation industry.

The company is one of the leading experts in aviation and is clients include Abu Dhabi, Chicago airport and Heathrow. It has also advised regional airports and governments and other parts of the public sector.

Thanet council asked the consultants to examine what sort of operation could work and the number of jobs likely to be created.

An earlier report by another expert consultancy was carried out in 2015.

The current owners who have renamed the site as Stone Hill Park, recently submitted a planning application for mixed-use development on the site, made up of 2,500 homes, employment floorspace to support the creation of up to 4,000 jobs, and a range of leisure and sports activities.

At the same time, the American consortium Riveroak is preparing to submit what is known as a Development Consent Order as part of its ongoing efforts to acquire the site to re-open an airport for mainly cargo operations.