Wollongong Lord Mayor Gordon Bradbery admitted to "falling on his sword" on Tuesday night when he voted against land rezoning plans for the Gleniffer Brae precinct that he had previously supported.
Cr Bradbery had earlier broken a six-all voting deadlock to overturn the council's December 10 decision to reject a rezoning proposal for the heritage-listed manor house, accompanying gardens and old school buildings.
But Cr Bradbery then voted against a rezoning proposal for the site that would have paved the way for the University of Wollongong to develop the site.
The Lord Mayor had previously voiced strong support for the university's proposal, even after it withdrew its interest in the site last December.
Last week he indicated he would push to have the zoning changes approved to give UOW the chance to return to the negotiating table.
However, Cr Bradbery caused shock when he voted against the rezoning proposal contained in a motion put forward by Liberal councillor Michelle Blicavs after the successful rescission motion.
Cr Bradbery yesterday stuck by his decision, saying while he was disappointed the university's plans were not realised, such an important issue should not hang on the balance of one vote.
"I voted it [the proposal] down because if this has to rest on one vote, either way, I don't think it's the way to proceed," he said.
"My understanding from the university was it wasn't prepared to proceed with its plans unless there was substantial councillor support, and last night [councillors were] not heading in that direction.
"From my perspective by the end of the debate I knew it [the UOW proposal] would cause too much division in the community and the council.
"If this went through I knew every step of the way would be contested and every development application would be challenged; the community would end up too divided."
Councillors eventually voted in favour of a motion from Cr John Dorahy that called for a report into the costs required to maintain the manor house and gardens and consideration of future options for the former school buildings.
As part of the motion, the council also resolved to keep Gleniffer Brae in council ownership and only consider future leases that showed a "benefit to the council and the community".
While the motion would allow the university to resurrect its bid, UOW Vice-Principal Chris Grange reaffirmed UOW would not proceed with its current proposal.