NASHVILLE — Seven groups that conduct voter registration drives are asking a federal judge to stop a new Tennessee law that threatens them with fines and criminal prosecution for failing to comply with a slew of regulations.

The motion for a preliminary injunction was filed on Friday in U.S. District Court in Nashville. It claims the law “undermines democratic principles.”

Plaintiffs include the League of Women Voters of Tennessee, the American Muslim Advisory Council, the Mid-South Peace and Justice Center, Rock the Vote, the Memphis Central Labor Council and HeadCount.

Several other groups filed a similar motion in federal court two weeks ago. Both groups want the judge to stop the law from going into effect in October by putting it on hold it until their lawsuits can be decided.

In Memphis, Early voting begins Sept. 13 and extends through Sept. 28. Sept. 3 is the deadline to sign up to vote in the Oct. 3 Municipal elections.