Opponents of the mayor have now collected enough signatures to force a recall vote.
The photos of Carmen Kontur-Gronquis featured her posing on a town fire engine wearing only a black bra and panties.
The mayor now gets five days to resign or submit a statement explaining her record in office.
After that, should she choose to stay on, a recall election would be scheduled and held with 35 days.
The mayor says she has no plans to resign.
