In this photo taken Monday, Jan. 12, 2015, Kansas Secretary of State Kris Kobach presides over the Kansas House while new members are sworn in during the opening day of the Kansas legislature in Topeka, Kan.

Topeka ? Civil rights groups demanded Tuesday in an open letter that Kansas Secretary of State Kris Kobach rescind his instructions to local election officials to throw out votes cast in upcoming local and state races by tens of thousands of people who registered at motor vehicle offices without providing proof of U.S. citizenship.

The executive director of the American Civil Liberties Union of Kansas, Micah Kubic, says Kobach is “deliberately creating chaos” for voters and “acting out of petulance.”

At issue is an email sent from Kobach’s office to county election officials last month outlining the state’s plans for implementing a two-tiered election system in the wake of a federal court order requiring Kansas to allow such voters to cast provisional ballots in the federal race. Kobach wants to allow election officials to throw out any provisional ballots in which votes were cast in state and local races and count only votes cast for president and U.S. Senate and House races.

The instructions come despite Shawnee County District Judge Franklin Theis finding in January that “no authority exists in the Kansas Secretary of State to encumber the voting process.”

Four civil rights organizations — the ACLU, League of Women Voters of Kansas, MainStream Coalition and Women for Kansas — said in their letter that Theis has already twice ruled the secretary of state lacks the legal authority to operate such a two-tiered election system.

“To disregard the court’s ruling and knowingly operate an illegal system would show a troublingly cavalier attitude towards the rule of law, as well as disrespect for voters themselves,” the letter said.

Kobach called the ACLU’s letter “nonsense,” citing the federal court ruling requiring the state to allow voters who registered at motor vehicle offices to vote in the federal elections.

“It is the judge’s order that carves out a special category of voters,” Kobach said in an email. “Kansas law requires all others to follow our proof-of-citizenship law. I will continue to enforce and implement Kansas law.”

Kobach contended that as secretary of state he has specific legal authority under Kansas law to ensure the state complies with the National Voter Registration Act, which is the statute that underlies the judge’s order.

The state had a similar process in place in the 2014 elections, during which a few hundred voters who registered with a federal form were affected.

Implementing it in the November election is estimated to affect as many as 50,000 people who register to vote when they get their driver’s licenses without providing the citizenship documentation.

Kobach has championed the documentation requirement as a way to prevent non-citizens from voting, particularly immigrants who are in the U.S. illegally. Critics contend the requirement suppresses turnout.