The office of Wausau Mayor Jim Tipple said the Marathon County Labor Council will have to reimburse the city for all expenses unless Republicans are allowed to participate in the parade, the Wausau (Wis.) Daily Herald reported Tuesday.
Tipple said he didn't have an estimate of what the parade will cost.
Labor Council President Randy Radke did not return a message seeking comment on Tipple's position.
The decision to bar GOP lawmakers is a reminder of lingering tensions between organized labor and the Republican Party in Wisconsin.
Radke said the council's decision to bar Republicans was prompted by anti-union legislation, particularly the changes to public employees' collective bargaining that became law this spring.
"I don't like it when politicians try to use us, use our event, for their personal gain," Radke said. "The Republican politicians in our area don't side with us, but now they want to make it look like they're on our side."
All three Republicans representing the Wausau area said they were disappointed by the council's decision.