The borough council wants the final decision to be taken out of the county's hands because of concerns that it is both the proposer of the project and the planning authority for it.
It is also planning a project in West Africa, as well as closer to home in London, cleaning up the Thames River in the runup to the 2012 Olympics, which are to be held in the city.
Banks said it had been reviewing options to take the project forward since its initial planning application had been refused by the City of York Council.
Forest YMCA has run a trial of the project for the past nine months in a car park while it applies for permanent planning permission for sites in Leytonstone and Walthamstow.
PlymWIN claimed the planning permission breached the EU Habitats Directive because it did not carry out the appropriate assessment for a project that could significantly affect a European site of importance.
Its web site is designed with the kind of coolly modernist sans-serif look that urban-planning nerds tend to like, and it includes all the trappings of an actual non-fake project: Mission statements, FAQs, press releases, 3D maps.