A 0.45-acre grassland plot in the canal basin is being marketed by Savills, with residents group Castlefield Forum strongly against development on the site.
Plot G is the piece of land between Merchants Bridge and The Wharf pub. The land value is estimated at £1.4m, with a deadline for expressions of interest of the 15 October. The freehold is held by Manchester Ship Canal Properties.
The plot has expired planning permission for a six or seven storey block of 45 apartments, or a commercial development with restaurant and hotel.
Castelfield Forum has called on Manchester City Council to retain Plot G as open space by contributing to acquisition and landscaping of the site in partnership with local and public-spirited businesses, developers and residents.
Carol Middleton, chairman of Castlefield Forum, said: "We fought a long, hard and successful five year battle to prevent inappropriate development of the site next to Plot G. It was a 'David & Goliath' victory with the proposals going to public Inquiry, which we and the Council won and the developer lost. They then sold the site to Brunning & Price who now run the stunningly popular pub, The Wharf, on the same site. We would fight an equally hard campaign to prevent inappropriate development of Plot G.
"We welcome new development in Castlefield. We'd love to see new development on the Cantina site by the Bridgewater Viaduct or along Bridgewater Street, and phases three and four of Potato Wharf. But Plot G is different. It lies at the heart of the canal basin. Keeping it as open space is crucial to the openness and parkland aspect of the area. Castlefield basin is truly unique, a jewel in Manchester's crown that should be protected for the present and future."