Residents of federally funded public housing will be required to show proof of U.S. citizenship or eligible immigration status under a new rule published Thursday by the U.S. Department of Housing and Urban Development.

The measure could displace nearly 80,000 people, including tens of thousands of citizens in mixed-status families, from their homes, according to the Center for Budget and Policy Priorities, a nonpartisan research and policy institute.

Since 1995, mixed-status families have been permitted to live together in HUD-funded housing as long as federal subsidies covered only eligible household members. The new rule may force these families to decide whether to remain together in nonpublic housing or split up their households.

“This is tearing apart families and sowing division,” said Marie Claire Tran-Leung, director of the Evictions Initiative Project and managing attorney at the National Housing Law Project.

The rule’s prior status, which allowed mixed-status families to live together, worked well for all parties, Tran-Leung said. Mixed-status households often paid a higher share of rent because their subsidies were prorated, experts say. If those families are forced to leave public housing, HUD will likely face financial shortfalls, Tran-Leung said.

About 20,000 mixed-status families, or 80,000 people, could be affected by the rule, CBPP’s data shows. About 37,000 of those are children, mostly U.S. citizens, CBPP said.

The rule is scheduled to take effect on Dec. 14.

Cara Tabachnick, CBS News