Texas ? For months, a fierce debate over an ordinance that would prohibit landlords from renting to many illegal immigrants has consumed this quiet north Dallas suburb.

The controversy peaked last week when Farmers Branch residents became the first in the nation to approve such a measure – by an overwhelming 68 percent to 32 percent vote. Similar apartment rental bans adopted elsewhere were decided by city officials, not voters.

The American Civil Liberties Union has asked a federal judge to block the ordinance but – barring a last-minute restraining order – enforcement will begin on Tuesday, said city councilman Tim O’Hare.

“The problems associated with illegal immigration are out of control,” said O’Hare, the lead proponent of the measure. “This is a very pro-American vote and a pro-American town.”

The newly approved regulation requires apartment managers to verify that renters are U.S. citizens or legal immigrants before leasing to them. Violators face fines of as much as $500. Exceptions will be made for renters who signed a lease before May 22 and families in which the spouse or head of household is in the U.S. legally.

“We welcome anyone to Farmers Branch that has a legal right to be in the country. But if you’re not, you’re not welcome here,” O’Hare said.