LA CROSSE, Wis. (WKBT) -

More and more landlords are getting behind a push against city renting guidelines.

Two landlords in La Crosse announced a lawsuit against the city back in May because of an ordinance that requires them to register their property annually.  Since then, the number of landlords joining the lawsuit has grown exponentially.

More than 30 landlords, representing some 200 or more rental properties across the city, have added their names to the lawsuit that started with just two plaintiffs.

"It just shows that there's a large amount of people who disagree with City Hall on this," said Bernardo Cueto, lawyer for the landlords. "They're trying to say maybe its a couple landlords, it's not - its a huge amount of landlords [who are] against this."

The lawsuit focuses in on an ordinance, passed by council members this spring, which requires landlords to pay a fee and register their properties with the city every year. That process includes an inspection of each property, and handing over the landlords' contact information. The plaintiffs say that violates state law.

"The state of Wisconsin's pretty clear that you cannot require more information of landlords than you do of all residential property owners," said Cueto.

That state law is relatively new - it was passed by the Legislature back in January, around the same time city officials crafted the ordinance.  Mayor Tim Kabat says they paid careful attention to stay within its boundaries.

"We feel very strongly that we complied with the intent and the letter of the law for what the state was proposing," Kabat said.

The city has had rental registries in the past that many call 'cumbersome' and 'confusing,' because there were two separate systems for traditional apartment complexes and rented single-family homes.  Kabat says this latest attempt to create a registry wasn't intended to discriminate against landlords, but to streamline the process into one uniform system and help revitalize deteriorating neighborhoods.

"[The ordinance's purpose] was to improve the overall quality of housing, to make sure rental housing is safe for their tenants, and to have a mechanism to do that," Kabat said. "That's why there was a registration program and an inspection program."

Kabat also said the state law in question allows cities to collect contact information of landlords in case of an emergency - meaning the ordinance is well within the boundaries of the legislation. Cueto disagrees.

"The city is trying to use that narrow ground - that they're allowed to set up any kind of registry - and saying, 'Instead, we're not going to use a registry to contact landlords for emergencies, we're going to use it to prohibit them from renting.'"

While the lawsuit makes its way through the legal process, all 34 landlords that are listed as plaintiffs don't have to follow the ordinance requiring them to register with the city. All other landlords in La Crosse have just a couple days - until the end of July - to register, or else face fines that could reach up to $3,000.

A judge is expected to make a ruling on the lawsuit Aug. 15.