Topeka ? One day before a decision is expected from their state party, Republican members of the state’s congressional delegation urged Thursday that GOP primary elections in Kansas remain closed.

Both the state GOP and the state Democratic Party can open their primaries to nonparty members — despite a long-standing Kansas law to the contrary — because of a recent federal appeals court decision.

Secretary of State Ron Thornburgh, the state’s chief elections officer, asked the two parties to decide by the June 10 candidate filing deadline. As of Thursday, neither party had.

The parties could keep their primaries closed, as they are now. They could allow participation by all nonparty members — even those registered with other parties — or they could expand participation only to unaffiliated voters.

State GOP Chairman Dennis Jones scheduled a news conference for 1 p.m. today at the party’s headquarters in Topeka to announce his party’s plans. Democratic Chairman Larry Gates said his party’s executive committee would meet Monday to discuss the primary and may poll other party leaders.

The five Republicans in the state’s congressional delegation — Sens. Sam Brownback and Pat Roberts and Reps. Jerry Moran, Jim Ryun and Todd Tiahrt — sent Jones a letter Thursday, urging him to keep the primary closed.

They said they believed firmly that only registered Republicans should be allowed to choose the party’s nominees.

“The November general election should offer voters a choice reflective of the views and values of each participating political party, whether it is the Republicans, Democrats or Libertarians,” they wrote. “This is a basic principle to which we believe the Kansas electoral system should continue to adhere.”

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

Not all prominent Republicans oppose opening GOP primaries to other voters. State Sen. John Vratil, R-Leawood, said allowing unaffiliated voters to participate was “an excellent idea.”

“We need to do everything we can to encourage everybody to participate,” Vratil said during an interview.

In April, the 10th U.S. Circuit Court of Appeals in Denver struck down an Oklahoma law that limited participation in that state’s primaries to party members and unaffiliated voters.

The appeals court said a state could not restrict a party’s ability to define who may participate in choosing its candidates.

Kansas recognizes four parties: Democratic, Libertarian, Reform and Republican.