Topeka ? Sedgwick County Republicans filed a lawsuit Thursday asking a court to stop the state from opening the Aug. 3 primary to unaffiliated voters.

The county Republican Party filed the petition in Shawnee County District Court against Secretary of State Ron Thornburgh, seeking to block him from opening the primary this year until state Republicans have discussed the issue at a convention.

Meanwhile, a Sedgwick County judge granted a separate request for a temporary restraining order nullifying the decision by state party Chairman Dennis Jones to open the GOP primary to about 400,000 unaffiliated voters statewide.

Mark Kahrs, the Sedgwick County Republican chairman, said Jones exceeded his authority by opening the primary and did so despite the objections of the state’s Republican congressional delegation.

“He didn’t even consult his executive committee,” Kahrs said.

Although a long-standing state law had allowed only members of a political party to vote in the party’s primary, a recent federal appeals court decision means the parties can open their primaries now can be opened to nonmembers. Thornburgh asked the Democrats and Republicans to decide by Thursday — the deadline for candidates to file — whether to open their primaries. Both parties had announced plans to allow unaffiliated voters to participate.

The lawsuit filed in Shawnee County against Thornburgh was assigned to Judge Charles Andrews and will be decided early next week, said Kent Vincent, an attorney for the county Republicans. State courts are closed today in observance of the national day of mourning for the death of former President Ronald Reagan.

Scott Poor, executive director and general counsel of the state GOP, declined comment.

Thornburgh said Thursday he was proceeding with plans to hold the election in August unless told otherwise by the courts. The first ballots are due to be mailed June 18 to Kansas military personnel serving outside the state.

Democrats and Republicans began conducting primaries in Kansas in 1908. The contests have always been closed, though unaffiliated voters have been able to participate by declaring an affiliation at the polls.

Republicans have expressed concern that Jones lacked the authority to unilaterally open the primary. Some also are worried about the impact it may have on the balance of power in the party.

Thornburgh said the potential impact of an open primary wasn’t his concern.

“My job is the election,” he said. “I’ll let the politicians worry about the impact.”

Those filing for office by Thursday’s deadline included a prominent Wichita Republican, former Mayor Bob Knight, who is challenging incumbent state Sen. Susan Wagle.

Knight, a moderate, lost the GOP nomination for governor in 2002. Wagle, a conservative Republican, has been outspoken in recent years on issues related to abortion and a human sexuality course taught by Kansas University professor Dennis Dailey.