The American Civil Liberties Union sued Florida on Friday to stop its controversial program designed to purge noncitizen voters from the rolls.

The ACLU says the program, which overwhelmingly targets minorities, needs approval from the federal government under the 1965 Voting Rights Act — a claim already made last week by the U.S. Department of Justice when it ordered Florida to cease the purge.

Florida Secretary of State Ken Detzner, who is named as a defendant, has said Florida already received permission years ago to clean the voter rolls of noncitizens.

But the ACLU argues that the specific processes for the noncitizen-voter program — a new effort by the state — never received federal approval.

What’s more, the program is too much of a burden on, and too much of a threat to, lawful voters, who could risk being removed from the rolls due to government error, the ACLU says.

“The state of Florida is violating federal law by subjecting citizens to this new and unnecessary requirement in order to exercise their right to vote,” Julie Ebenstein, an ACLU Florida staff attorney, said in a written statement. “We are asking the court to protect the right to vote and stop this unlawful, targeted voting purge.”

Detzner’s office couldn’t immediately respond to all aspects of the suit, which was filed late Friday afternoon. But it insisted the program is fair and needed.

“We have a year-round responsibility to ensure that the vote of a U.S. citizen isn’t diminished by the vote of a non-citizen, and we take this responsibility very seriously,” spokesman Chris Cate said.

“We are not aware of any eligible voters who have been removed from the voter rolls as a result of our efforts to ensure the integrity of Florida elections,” he added. “However, multiple people in multiple counties are coming forward and admitting that they are not a citizen and should be removed from the rolls, some of whom have voted.”

So far, about 40 noncitizens have been found on the voter rolls in eight of the state’s 67 counties. Six of them may have voted, which is a felony. It’s also a felony for a noncitizen to register to vote.

More than 500 people on a purge list the state has compiled have been determined to be actual U.S. citizens entitled to register and vote.

Among them: Murat Limage, a Hillsborough County resident who became a citizen on Nov. 1, 2010, and is a named plaintiff in the suit.

He was flagged as a potential noncitizen because the state compared its voter rolls with a motor-vehicle database, which only reflected his immigration status when he got a driver’s license in November 2008 – two years before he became a citizen.

State officials say they want more updated records from the federal government, but the request has been refused.

On April 13, Limage received a letter notifying him that he had 30 days to prove he is a citizen to ensure that he remained a registered voter.

Limage provided his passport to the Hillsborough supervisor of elections and was told he was OK, but he received no written notification.

Limage “remains concerned that he will not be permitted to vote in the upcoming election,” the suit says. Another voter who faces similar circumstances, Pamela Gomez, is also a named plaintiff, along with a Hispanic-voter advocacy group, Mi Familia Vota Education Fund, which claims the voter purge is interfering with their work, which is largely in Hillsborough County.