In a lawsuit filed Friday, the owners are asking a Superior Court judge to grant the increase and find that the city's rent-control law violates the state constitution. The suit also seeks unspecified damages.

"Why would City Council members ignore property rights, which are part of our core values and have been central to our success as a nation?" Mark Alpert, the owners' attorney, said in an e-mail. "Could it be they see a block of votes?"

Cavalier's current rents, he said, are "insanely low."

City staffers say park owners already make a reasonable return.

"Our rent control ordinance has been determined to be constitutional in prior court proceedings, and I'm not concerned that the court's going to find otherwise here," City Attorney John Mullen said.

The city's mobile home parks provide affordable housing for many low-income residents. Cavalier, located near the Interstate 5 interchange at Oceanside Boulevard, has 346 spaces with an average monthly rent of $350.

That's less than at comparable rent-controlled parks in the city and far below "reasonable, fair market" rents, the owners argue. In April, they sought permission from the Manufactured Home Fair Practices Commission, a council-appointed panel that oversees rent control, to charge $600 per month.

Park residents have said higher rates could price many of them out.

The commission denied the request, and a retired judge affirmed the decision on appeal, saying evidence produced by the commission was "more credible" than that of the park's owners.

Oceanside has had mobile home park rent control since the 1980s. The law permits annual rent increases of up to 75 percent of the Consumer Price Index. If owners want more, they must ask the commission for a special adjustment.

In what may be a contingency plan should the lawsuit fail, Cavalier's owners recently notified residents they plan to subdivide the property and offer the lots for sale. Doing so could wipe away local rent-control protections.

Call staff writer Craig TenBroeck at 760-901-4062.