The Eden project is seeking £40m to fund an expansion project, to include a third bio-dome with semi-desert conditions, but admits there is much work to be done before plans can be realised.

A spokesman said all ideas are possible but only if the necessary backing can be found: 'It would be lovely to be able to go ahead if funds can be raised.'

As one of the Millennium Project's most successful schemes, Eden attracted about 1.85m visitors during its first year of opening and has proved to be a significant financial boost to the surrounding area.