Former jockey Allan Robinson turned his back on running mate Councillor Aaron Buman today and instead handed out "Vote Robbo" cards that backed Jeff McCloy for lord mayor.
Cr Buman only learned of the move this morning.
It left him without booth workers across Ward 4, where Mr Robinson had been his lead candidate and was organising volunteers on polling day.
A furious Cr Buman, who is popular in Ward 4, confronted Mr Robinson at a polling booth at Shortland. Cr Buman said Mr Robinson had been given dozens of signs and hundreds of how-to-vote cards.
"Looking back I really wish I'd chosen quality people, rather than people I thought had a profile," he said.
Mr Robinson said today that he still supported Cr Buman, but that he could not stomach the preference deal that was struck with Labor.
"We had a meeting and he told us where he put our preferences," Mr Robinson said.
"I'm an independent. What right has he got to give away my preferences.
"Aaron Buman is a good man, but is he ready to be lord mayor?
"Jeff McCloy is ready."
Rumours about the defection have been circulating since Mr McCloy endorsed Mr Robinson in the ward.
The Newcastle Herald asked Mr Robinson about them on Thursday, but he said at that time he did not want to comment.
Cr Buman had also heard the whispers, but said he had been reassured by Mr Robinson only a few days ago.