"Councillors have already censured Len Brown for misusing funds but clearly the line in the sand is being ignored," said Jordan Williams, Taxpayers' Union executive director.
"A recall option would enable ratepayers to petition for a vote to fire a shameless [politician] who lacks any respect for those who pay the bills."
Recall elections were common in the United States, where the National Council of State Legislatures said about three-quarters of recall elections were at the city council or school board level. Arnold Schwarzenegger was elected Governor of California in 2003 thanks to a recall election.
The new bathroom for Mr Brown cost $10,000. The dressing room included an $800 wardrobe, ironing board and - according to plans - a two-seater couch.
A spokesman for Brown told the Herald on Sunday that Auckland Council, not the mayoral office, made all decisions on what facilities to include in Brown's new office.
A report released one year ago found Mr Brown used his council phone to make nearly 1,400 personal calls and texts to his then-mistress Bevan Chuang. He also failed to declare more than $39,000 in free hotel rooms and upgrades.
The Taxpayers' Union was co-founded by Mr Williams and right-wing blogger David Farrar