The residents lease the ground under their manufactured or mobile homes in Tricia Meadows, a community of about 400 homes.
Tricia Meadows was an early success story under the state Supreme Court's affordable-housing rulings, which found that suburban municipalities had an obligation to provide for low- and moderate-income housing. The discrimination case was brought by a black family in the 1970s.
Residents were stunned when they received a letter from their landlord, Davis Enterprise, in March notifying them their rents would rise to market rates in 2014, their lawyer, Paul Leodori, said. Most would increase from $224.50 to $457 a month, he said.
"They don't have the money. They built their lives around anticipating that this is where they are going to live until the end of their lives," Leodori said in an interview Friday.
A letter from the landlord's office informed residents the terms of a Superior Court judgment and the rent controls under which the development was built in 1984 expire Dec. 31.
However, the lawsuit contends that expiration was not included in the lease agreements, and therefore a rent increase would violate consumer-protection laws.
"The crux of the issue is that was never disclosed when these people purchased their homes," Leodori said. "None of them were ever told that the ground rent is going to double."
Davis president Miriam R. Nase could not be reached for comment Friday.
Mount Laurel has about 900 other affordable-housing units, all with waiting lists, officials said.
Affordable-housing advocates estimate rent-control restrictions on 10,000 apartments and townhouses will expire within the next 10 years.