Plans for the revolutionary eco-village, which could see homes, offices, restaurants and community facilities such as GP surgeries floated off Preston Docks, would cost between £10m and £40m to construct, sustainable development experts NGM has said.

Despite the credit crunch, the firm says it has cash available to fund the scheme – although the idea is only a proposal at this stage.

The company is awaiting the results of a council-commissioned feasibility study on the Riverworks project before deciding whether the scheme would be appropriate for Preston.

Bosses at the company insist they would not look to flood the Ribble with homes and would want to see swathes of water given over to leisure and sports.

Derek Cochrane, director at NGM, said: "It is very important to us that whatever the end result is, it is mixed use. We want to see not only structures but also watersports.

"We are waiting on a masterplan being put together and if it is agreed by everyone that floating buildings would be appropriate we can move very quickly."

Plans could be drawn up "within weeks" if the study is positive about the scheme. If approved by Preston Council, NGM says the community could be completed within 18 months.