Butler Mayor Tom Donaldson’s lawsuit against the city and three council members may hinge on a union contract.

Donaldson sued the city and council members Kathy Kline, Michael Walter and Corey Roche in December, protesting the promotions of two Butler firefighters who had not taken civil service exams.

The testing requirement was unanimously approved in September 2015, but the union contract for firefighters was approved in December 2014 and took effect at the beginning of 2015.

Judge Marilyn Horan said during a hearing Tuesday morning that the timeline is an issue.

Horan said the contract, which ends at the end of this year, was agreed upon before the civil service testing was enacted.

“They weren’t looking at a testing paradigm,” she said.

Attorney Larry Rodgers, who is representing Donaldson, argued the contract does not contradict the testing requirement.

“It’s a management prerogative,” Rodgers said.

Horan said the lawsuit seemed to be based on a retroactive application of the civil service testing requirement.

Rodgers insisted that was not the case, but Horan was not swayed.

Attorney Leo Stepanian II, who is representing the city and council, said the ordinance adopting the testing is problematic.

“They can’t now ignore the contract,” Stepanian said.

In May 2016, Jim Kaufman was promoted to captain and Donald McCoy was named lieutenant. Neither had taken the civil service exam at that point.

Donaldson’s complaint seeks the rescinding of the promotions and reimbursement of attorney fees.

Stepanian asked Horan to dismiss the case due to the firefighters and the union not being named defendants.

“They’re indispensable parties,” he said. “They haven’t had an opportunity to be heard.”

Stepanian said Councilman Ken Bonus should be named even though he was not in office when the firefighters were promoted.

According to Stepanian, the entire present council should be named as defendants.

Stepanian said the lawsuit should be thrown out on those grounds.

“We request the complaint be dismissed,” he said.

Rodgers argued the union should not be a defendant because the testing is not contrary to contract language.

“The union really has no dog in this fight,” he said.

Horan said it’s premature to know which parties would be indispensable.

She did not state when there would be a ruling on any preliminary objections or a possible dismissal.

Donaldson and the council members did not attend the hearing.