The steering or leadership group of 52 would be in addition to a stakeholder forum (of 200 representatives), an expert advisory group and a project team.
Earlier, Mrs Fletcher seconded an unsuccessful move by councillor Mike Lee for a spatial plan project steering group made up from the existing gulf forum, expert advisory group and project team.
She said the spatial plan had been promoted by the gulf forum, which included councils for the Waikato, Hauraki Plains and Coromandel.
But she no longer believed it would make the hoped-for improvements in the environment of the gulf's fish and birds, nor solve the conflict between conservation and farming and fishing.
"We have been hijacked by other agendas around Treaty [of Waitangi] settlements and why we haven't been able to get a consensus here today is not necessarily around the ongoing stewardship of the gulf."
Deputy Mayor Penny Hulse said the topic was deferred until next month to allow talks with the Hauraki Gulf Forum and Maori.
Guidance from the council's Independent Maori Statutory Board members would be sought on the question of an appropriate partnership.