The education and union supporters demonstrated outside Weiner's apartment building Friday, carrying signs reading "We Don't Want a Weiner For Mayor" and "Don't Let The Sexting Perv be Mayor," a reference to the sexting scandal that chased Weiner from Congress, the New York Daily News reported.
The inflatable rat has been a tool union activists have generally deployed against non-union businesses.
Weiner said using it against him was "diminishing the value of the rat."
"The rat used to mean something," he said. "And I think the labor unions who do make it mean something besides scab work are kind of making a mistake."
Mona Davids, who works for the union representing parent coordinators, said Weiner's concerns are misplaced.
"Instead of being concerned about the rat, he should be concerned about the 1,400 parent coordinators of this city and the parents and students who count on them," she said. "We use the rat to protest anyone who's anti-union and anti-woman, and Weiner is certainly both of those things."