Former Shellharbour mayor Kellie Marsh says she was "totally ambushed" by fellow Liberal and new deputy mayor Paul Rankin when she was rolled in last week's mayoral vote.
Speaking publicly for the first time since she was dumped from the top job, Cr Marsh attacked Cr Rankin, saying she felt "deceived" by his last-minute decision to challenge her.
The Liberal split threatens to tear a rift in the council just 12 months into its five-year term.
"I feel ... and the supporters that voted for us . . . feel that Cr Rankin has shown that he's Paul and his amazing technicolour turncoat," Cr Marsh said.
"He's spouting about communication and yet he totally ... ratted and back-doored his own colleague who's worked in with him and supported him and got him over the line, quite frankly, and our supporters are very, very disappointed in him."
Cr Marsh also said she was disappointed at comments other councillors had made about her.
"I honestly feel that my record of what I did for the 12 months ... with small business, youth, families and everyone in our city ... does speak for itself," she said.
Shellharbour City's seven councillors choose the mayor every 12 months. Labor's Marianne Saliba was elected mayor last week with four out of seven votes.
Cr Rankin also raised his hand for the job, with support from independent Helen Stewart.
Cr Marsh found out about Cr Rankin's challenge minutes before.
A Liberal candidate from last year's council election, Harry Gooden, said he felt "disillusioned" at Cr Rankin's decision, which "gave the vote to the Labor Party".
But Cr Rankin claimed Cr Marsh did not have the numbers to become mayor and "doesn't have a mortgage" on deputy mayor.
He previously denied his decision to run was an ambush, and said he made up his mind only that afternoon after learning Cr Stewart would not support Cr Marsh.
"I believe that we need to have a Liberal in one of those two positions and . . . the way the numbers fell I stuck my hand up and I got the support," he said.
In response to Cr Marsh's allegations, he said: "If that's the way she feels, that's the way she feels."
He also said it was "not correct" that his actions had angered Liberal Party supporters, stating that Mr Gooden was the only person he knew who was upset.
He did not believe it had damaged the Liberal brand.
"I can understand Kellie being upset about it, but at the end of the day, could it have turned out better? It probably could have. Do I have any regrets about it? No, I don't," he said.
Cr Marsh thanked the community for its support.
"The reason I've come out is because I've had so much support," she said. "So it's not sour grapes, believe me."
Liberal MP for Kiama Gareth Ward declined to comment on the vote, but said Cr Marsh had done an "outstanding job" as mayor.