Doubts have been raised over the prospect of Thanet District Council forcing a buyout of Manston airport after it emerged the American consortium that wants to acquire it has failed to provide the authority with crucial financial information.

In a statement issued by the council on its website, it said that it had issued what was described as a 'final demand' to RiverOak for the information.

The statement said: "As part of its commitment to review the position on the Manston Airport site, Thanet District Council has today (Wednesday, August 5) issued a final request to Riveroak’s solicitors for the financial evidence promised by the company in early July."

It went on: "The council reopened discussions with Riveroak following a Cabinet decision on 14 July which recommended the council review its position.

"Since that time, the council has corresponded with Riveroak to try to establish whether they could be considered a suitable indemnity partner for a compulsory purchase order on the site."

"The council cannot take forward any decision to appoint an indemnity partner until it is satisfied that there is evidence that the finances, or guaranteed access to finances, required to underwrite a CPO (compulsory purchase order) process are in place."

Ukip council leader, Cllr Chris Wells, said: “We have to be absolutely certain that the financial evidence is in place. I look forward to receiving the information as promised to provide the assurances we need in order to progress.”

However, RiverOak issued a statement saying it remained committed to trying to secure a Compulsory Purchase Order for the airport - although the statement made no comment on the council's demand and did not say whether it had provided the information required.

The statement said: "RiverOak remains resolute in its interest in partnering with Thanet District Council in a CPO for Manston Airport. While we do not plan to respond directly to the recent release put out by Thanet Council, we can say that we are fully committed to this project and have a senior team in England which is seeking a mutually agreeable resolution as soon as possible."

South Thanet MP Craig Mackinlay said: "I am concerned about this. As far as I am aware, Riveroak has done everything that has been asked of it. It does feel that we are not very much further - it is a bit like snakes and ladders, we take one step forward then two steps back."

It is unclear why RiverOak has not yet provided the information but the council's insistence this represents the last chance raises serious doubts about whether a CPO will go ahead and reflects unease among some councillors that RiverOak may choose to walk away from the proposed partnership.