FILE – In this June 5, 2012 file photo, voting ballots are stacked and ready as voters wait in line to cast their ballot in Milwaukee.  AP Photo/Jeffrey Phelps, File)

Opponents of a strict new voter identification law set to go into effect for the first time in this year’s elections are asking the Supreme Court to block the law, arguing there isn’t enough time to properly implement the law before Election Day.

Two voting rights groups, the American Civil Liberties Union and the Advancement Project, representing a number of Democratic-leaning and voting rights organizations, filed a petition with Supreme Court Justice Elena Kagan seeking an emergency stay halting the new law’s implementation.

The petition comes after an en banc panel of the 7th Circuit Court of Appeals in Chicago on Friday split evenly on whether to hear a challenge to the law. The 5-5 decision leaves an earlier three-judge panel’s ruling in favor of the law intact, reversing an order from a federal judge in Wisconsin this spring to strike it down as unconstitutional.

“Thousands of Wisconsin voters stand to be disenfranchised by this law going into effect so close to the election,” Dale Ho, director of the ACLU’s Voting Rights Project, said in a statement. “Hundreds of absentee ballots have already been cast, and the appeals court’s order is fueling voter confusion and election chaos. Eleventh-hour changes in election rules have traditionally been disfavored precisely because the risk of disruption is simply too high.”

Attorney General J.B. Van Hollen’s (R) office did not have an immediate reaction to the filing.

The law requires voters to show government-issued identification, including some but not all student identification cards, when they arrive at their polling places. County clerks are contacting the hundreds of voters who have already cast ballots to ask them to provide copies of their identification before their ballots are counted.

A poll released Wednesday showed about one in five voters in Wisconsin doesn’t know about the identification law, which opponents say could lead to mass disenfranchisement. The Marquette University poll did show almost two-thirds of Wisconsin voters back a requirement that voters show identification at the polls.

The state legislature’s budget committee will hold a hearing next Tuesday to consider election officials’ request for $460,000 to run advertising on television, radio and online to inform voters of the identification requirements, the Milwaukee Journal-Sentinel reported. The paper said the fact that the Joint Finance Committee called such a quick hearing is a sign that legislators intend to allow the Government Accountability Board to spend the money.

Wisconsin’s voter identification law was initially approved by the Republican-dominated state legislature in 2011. But the case has been bottled up in courts ever since. The state Supreme Court has ruled twice in favor of the measure.

And plaintiffs could face long odds at the Supreme Court. In 2008, justices upheld Indiana’s voter identification law; the three-member panel of 7th Circuit judges last month called the two laws “materially identical.”

Rick Hasen, a voting rights expert at the University of California-Irvine and author of the Election Law Blog, called the 7th Circuit ruling “disingenuous.”

“[T]he voter id law should not be implemented in such a haphazard way risking the disenfranchisement of thousands of voters,” Hasen wrote last week, after the 7th Circuit’s decision.

About 300,000 Wisconsin voters don’t have the forms of identification required to receive a ballot, a lower court found.