ROCHESTER, N.Y. -- Rochester Mayor Lovely Warren faces new accusations of favoritism, with Democratic primary challengers alleging special treatment for Uber over other ride-hailing companies.

Rachel Barnhart has filed a complaint with the New York State Joint Commission on Public Ethics alleging that Jeremy Cooney, a public relations professional working with Uber and Warren's former chief of staff, engaged in illegal lobbying activity when he helped organize a job fair at city hall for the service.

"He was in contact with government employees and government officials. He's a lobbyist whether he likes it or not and he has to register as such," Barnhart said.

Barnhart believes Cooney should be registered as a lobbyist with the state of New York.

Brian Curran, the city's legal counsel, argues state law defines lobbying as the attempt to influence or defeat the passage of legislation.

"At this point, the state's already passed a law authorizing Uber and Lyft and other companies to operate so there is no legislation pending before the city."

Barnhart notes Rochester would have the option to opt out of the soon-to-take-effect law.

"It's very clear why Uber is still trying very hard to lobby city officials. They want to make sure they're able to stick around," Barnhart said.

"As far as I know, no one has proposed doing that in Rochester so there's no proposal currently pending before the city council or the mayor," countered Curran.

Barnhart is also asking the city's ethics board to to investigate possible violations, including whether Warren gave Cooney special access.

"It's very clear that his personal and professional relationship with Mayor Lovely Warren is why yesterday was allowed to happen," Barnhart said.

The other challenger, James Sheppard, issued a release stating, in part:

"Warren’s decision to host a job fair at City Hall sponsored by Uber, the sole client of her former chief of staff Jeremy Cooney, was the latest in a series that put the interests of her friends and supporters ahead of the interests of Rochester’s residents."

"I'm not going to get down in the mud with anybody, of trying to make an issue of something that is not. The fact of the matter is we're providing opportunity and jobs to our community," said Warren.

Mercury Public Affairs, speaking as a representative of Uber, released this statement:

"It's always sad and unfortunate to watch a flailing candidate at work. We actually know and understand the law, and are careful to fully comply with it. This case is no exception and any review by competent people will validate our position."

Warren saids the city is willing to open its doors for any ride-hailing service and is already planning a similar event with Lyft.

This isn't the first time the mayor's been accused of showing favoritism. Shortly after taking office, she was criticized for hiring her uncle as a bodyguard.