The owners of the former Manston airport have made it clear flights will not return to site, saying “the sums do not stack up”.

In a full page advert published in the Thanet Extra this week, Trevor Cartner and Chris Musgrave reaffirmed their plans to create 4,000 jobs over 20 years and discredited RiverOak, the US company which tried to buy the site to reopen the runway.

The duo, who own Discovery Park in Sandwich, a business centre home to more than 100 companies, also revealed former owner Ann Gloag retains a 20% stake in the site.

However they said she has no decision making power, a position which has been disputed by campaigners who support the transport select committee view she has a "a de facto veto" over the pair.

“The future of the site of the former Manston airport has understandably divided opinion,” said Mr Cartner and Mr Musgrave.

“A lot has been said by those who would like to see aviation services start again. Less has been said about our vision for the site.

“Today we intend to start putting that right and dispel many of the myths that have sprung up over recent months.

“Nothing, as yet, is set in stone but we believe our approach will achieve the kind of economic benefits, not least in terms of sustainable jobs, the airport was never able to bring.“

The pair confirmed a figure published by Kent County Council last week which said the airport lost more than £100 million under private ownership, following its sale by RAF Manston.

In an attack on airport bidders RiverOak, they said they “are not airport specialists” and “are best known as a relatively small real estate (property) investment fund in the USA”.

In an exclusive interview with Kent Business last year, the property developers revealed it is their intention to turn the airport into a centre for manufacturing business.

A draft master plan for the site will be ready by early summer, with a public consultation on their proposals following.

Campaigners for the airport have published a rival advert in support of a takeover by RiverOak, with the help of a compulsory purchase order issued by Thanet District Council.

RiverOak chief executive Steve DeNardo said: “RiverOak remains absolutely committed to reviving Manston as an operational airport and building a thriving and profitable air cargo, aircraft recycling and reliever airport operation there for the long term benefit of not only east Kent, but users of the whole of the London airports system too.”