NEWNAN, Ga. – Voting rights groups asked a federal judge Friday to stop Georgia's attempts to verify the identities and citizenship of new voter applicants, arguing they amounted to a “systematic purging” of rolls just weeks before the election.

The groups filed a federal lawsuit Thursday saying that the immigration checks, which involve matching the applications with driver's license and Social Security data, must first be approved by the Department of Justice.

Georgia is not alone in being questioned about the way it has been verifying voter records and “purging” voters from the rolls before Election Day. Methods are being scrutinized across the country, including in several swing states that could determine who becomes president in a close election.

But Georgia is among several states with a history of discriminatory voting practices that must clear an additional hurdle. It must get federal approval before changing election policy under the Voting Rights Act of 1965.

Georgia election officials say they have no problem submitting election policy to Washington.

But Republican Georgia Secretary of State Karen Handel said the checks were an effort by her office to follow federal guidelines to ensure the integrity of the vote and that those eligible are casting ballots.

“We're simply trying to follow the law,” she said after the hearing.

The federal lawsuit came a day after the Department of Justice said the state's action to verify citizenship using Social Security numbers violated the 1965 voting law because the policy did not receive federal clearance first.

The Justice Department says Georgia officials made some 2 million requests to check the Social Security numbers of newly registered voters – far more than any other state, indicating a change in election policy. State officials question so high a number, since just 406,000 registered in Georgia during the same period.

Some counties have sent letters to residents asking them to provide proof that they're eligible to vote or be disqualified based on those checks.

Handel said no registered voters have been stricken from the rolls because of the immigration checks. Of the 120,000 new voter applications the department is now handling, she said officials have questioned an estimated 3,000. Some 2,000 involve citizenship, she said.

“You can see this is an extremely critical component of the process, to be able to verify the voter identification process, that those individuals are indeed who they say they are,” she said. “That's something I think we should be able to agree on: Any individual who is not eligible to vote should not.”

The lawsuit centers on Jose Morales, who became a U.S. citizen in November 2007 and registered to vote last month.

Two weeks after he registered, a letter from Cherokee County demanded he provide evidence of his citizenship, according to the complaint. The lawsuit does not specify how county officials flagged his application to check for citizenship. He received his voting card soon after he showed his passport to the registrar's office, but this week another letter asked him to again verify his citizenship and warned him his name could be removed if he did not.

The voting rights attorneys blasted the letters as an intimidation tactic.

“This is precisely the kind of systematic purging that federal law bars,” said Elise Shore, an attorney for the Mexican American Legal Defense and Educational Fund. She said it “creates a barrier that discourages people from showing up at the polls.”

The federal judge made no immediate decision on whether to order the state to stop the checks.

States have been trying to follow the Help America Vote Act of 2002 by removing the names of voters who should no longer be listed.

Elsewhere in the country, Colorado officials were reviewing the way the state deals with potentially ineligible voters after questions were raised about whether it is violating federal law by putting such voters on a “cancel” list within 90 days of the election.

A federal judge in Ohio on Thursday ordered the state's top elections official to verify the identity of newly registered votes by matching them with other government documents. That includes matching new registrants' voting information against databases maintained by Ohio driver's licenses and the Social Security Administration.