Birmingham schools earmarked to be turned into city academies may miss out on millions of pounds of investment.
Education chiefs have identified seven schools they want to turn into the flagship Government centres aimed at addressing under-achievement in urban areas.
Under the controversial programme, schools are knocked down and replaced with a #25 million new building, with a #2 million contribution from an outside sponsor.
Birmingham, however, is in negotiations with the Department for Education and Skills for a customised version of the concept.
Unlike the Government model, the authority would retain control over admissions and more than one sponsor would be recruited, preventing any one backer gaining too much influence.
But Councillor Les Lawrence (Con Northfield), the authority's cabinet member for education, also admitted its model might not involve a rebuild or cash contribution from sponsors.
"We don't know whether it is rebuild," he said. "If you have got facilities already within a community it is illogical to knock them down.
"It is more about the environment in which children learn in. Just building a brand new building isn't necessarily a benefit. It may be a refurbishment and that can be quite a major change."
Coun Lawrence said contributions from sponsors could be in the form of "resource" instead of a #2 million cash injection.
"Because we have multi-sponsors, some may pay in kind with knowledge, expertise or capability and particular ways of doing things.
"That is a better way of looking at that kind of relationship so organisations and individuals are more attuned with developing an ethos."
However Bill Anderson, deputy general secretary of the Birmingham branch of the National Union of Teachers, claimed the bigger benefit to schools would be lost.
"What is in it for the schools if they are not going to get anything other than something in kind?" he said.
"They are not necessarily getting the extra funding for it. It seems to be that people will be able to take over schools and they don't even have to dip into their pockets.
"What is going on here?"
The seven secondaries Birmingham is proposing should become city academies are: The Heartlands High in Nechells; The College High in Erdington; Kings Norton High in Kings Norton; St Alban's in Highgate; Sheldon Heath; Shenley Court in Selly Oak and Harborne Hill in Edgbaston.
Coun Lawrence said it was unlikely a final decision on whether its proposals had been accepted by the DfES would be reached until late May - after the local elections.
Mr Anderson said the delay suggested the authority was pushing through the plans without proper public consultation.
"The stuff is dribbling out," he said.
"Why not put this to the electorate of Birmingham? If there is anything the political parties ought to go public on it is the future of education.
"All parties standing for this city should come out and debate what is happening here."