Surveyors Nolan Redshaw is urging the Co-operative to reconsider its decision to refuse to remove a covenant, which it says is blocking the regeneration of Bacup town centre.
Consultants working for a major supermarket chain, thought to be Morrisons, have hit out at the Co-op for not lifting legal restrictions which prevent the building of a new store.
The covenant was put in place by the Co-op on the derelict Horace's nightclub, when it disposed of the land four years ago.
Developer Bridge Properties stated the Co-op has previously agreed to remove the covenant to allow the scheme to take go-ahead, but the Co-op said no formal commitment was made. Co-op bosses say they are under no obligation to release the covenant.
Nolan Redshaw said supporters of the multi-million pound project say it is desperately needed. They say the project would cost more than £7m and create more than 100 jobs and would also see the renovation of the Irwell Mill and a town centre office site.
A spokesman for Bridge Properties said: "I went to the Co-op and they agreed to lift the covenant four months ago provided I paid their legal fees. We prepared the document ready for signature and the Co-op then said that they had changed their mind, as they didn't think there was a need for another supermarket in the town centre."
Bridge Properties has been working on plans for the supermarket for nearly five years and are ready to update an existing planning permission, which was granted some years ago. However, Bridge Properties fears the whole project could now be scrapped if other minor landowners lose patience and decide to sell up.
Paul Nolan, of Nolan Redshaw in Bury, said: "A vital town centre regeneration scheme of a derelict mill and office site in town centre Bacup has been placed in jeopardy by the Co-op. The development is desperately needed to regenerate the town centre and we hope that for the sake of the future of Bacup, the Co-op will change its decision and lift the covenant."