A new report has concluded that there are no major issues preventing plans for the construction of a £40bn floating airport off the Essex and Kent coasts in the Thames Estuary.

The feasibility study, which was carried out by the Thames Estuary Research and Development Company (TERDC), called for further studies to investigate the ecological impact of the scheme but found no "insoluble issues" to halt the proposals. London mayor Boris Johnson commissioned the study into the plans, which could result in the construction of an airport with up to six runways in a bid to prevent the need to expand Heathrow Airport and meet increased demand.

Engineer Douglas Oakervee, who helped with a similar project in Hong Kong, and Bridget Rosewell, the Greater London Authority's (GLA) chief economic advisor formed TERDC to carry out the report. In the report, Oakervee said: "The report at this stage does not favour any specific location. It does, however, note that the area of the Thames Estuary does not present any insoluble issues.

"Even with three new runways being built at the existing airports, current government predictions make clear that further airport capacity is required by, or before, 2030. If this be the case, work on the Thames Estuary Development Study, which would embrace all of the planning and reports, needs to commence no later than the summer of 2010." However, the proposed construction of an airport in the Thames Estuary has been met with strong opposition from a new campaign launched by Medway Council, Kent County Council and the Royal Society for the Protection of Birds (RSPB).

According to a spokesperson for the RSPB, the report fails to deal with a number of concerns raised by the proposals, including what it calls the assumption that increased airport capacity is necessary, as well as the additional infrastructure a new airport would require. Medway Council leader Rodney Chambers said: "The airport and the infrastructure needed to serve it would cost a ridiculous amount of money and it would devastate the environment which includes Sites of Special Scientific Interest and internationally important areas where hundreds of thousands of birds migrate to annually."

RSPB regional director Chris Corrigan added: "As well as massive environmental damage, there could be a significant risk of birdstrike, as the Thames Estuary is a hub for hundreds of thousands of migrant birds. Even with an aggressive bird hazard management programme, the bird strike hazard would be up to 12 times higher than at any other major UK airport."