The mayor should expect a few slashed tires and maybe a brick thrown through his window.

(Reuters) — The mayor of a Wisconsin town said on Tuesday a local labor council would have to reimburse the city up to $2,000 for a Labor Day parade if organizers exclude Republican lawmakers from attending.

The move in Wausau, Wisconsin, came after a county labor official said last week that Republican politicians were not welcome at the event due to their party’s stance against collective bargaining when state lawmakers voted to curtail it earlier this year.

Wausau Mayor Jim Tipple told Reuters on Tuesday that the decision to exclude elected Republicans “flies in the face of public policy.”

“This is not a political rally, it’s a parade, for God’s sake,” Tipple said, noting that taxpayer money is used by the city to pay for staging the event. Tipple’s office is nonpartisan, and he claims no affiliation with either political party.

He said the annual cost of the parade, including insurance, setting up and taking down a stage, and police personnel, runs anywhere from $1,500 to $2,000 each year.

The Republican-backed collective bargaining limits made Wisconsin the center of a battle over union power this year.

The fight propelled the state to the forefront of a wider national struggle as Republicans who took control of many statehouses in last year’s midterm elections moved aggressively to shrink government and made reining in public unions a top priority.

“It should come as no surprise that organizers choose not to invite elected officials who have openly attacked workers’ rights or stood idly by while their political party fought to strip public workers of their right to collectively bargain,” Marathon County Labor Council President Randy Radtke said in announcing the decision.