File: Prince William Board of County Supervisors Chairman Corey Stewart (R) (Dayna Smith/For the Washington Post)

The Prince William County court case over whether primary elections should be held for Board of County Supervisors Chairman Corey A. Stewart and three GOP colleagues has a hearing scheduled for Friday, officials announced Monday.

Stewart (R), Sheriff Glenn Hill and Supervisors Martin E. Nohe (Coles) and Maureen S. Caddigan (Dumfries) filed the lawsuit last week to overturn a county Electoral Board decision against staging primary elections after a local party official missed a state deadline for requesting that they be held.

The incumbents hope to avoid a less predictable firehouse canvass or caucus nomination, which would draw fewer voters and more likely favor lesser-known opponents.

Under a state code governing elections, incumbents who were elected through a primary have the option of seeking nomination for another term through another primary.

But those candidates must also be confirmed by the state Department of Elections. The agency chose not to do so after the paperwork requesting that action was filed 36 hours after the Feb. 24 deadline. The county Electoral Board’s two Democrats — Chairman Keith A. Scarborough and Jane M. Reynolds — cited that decision in their vote against staging primary elections. Guy Anthony Guiffré, the sole Republican on the board, voted for primaries.

The lawsuit, filed in the county’s circuit court, claims that the candidates have the right to a primary election under a different portion of the state elections code that allows political parties to determine the method for nominating their candidates.

On Monday, the Virginia Supreme Court designated retired Arlington County judge Paul Sheridan to hear the case.

Prince William’s circuit court judges recused themselves because the lawsuit involves county officials they may have interacted with outside of court, a circuit court official said.

Stewart expressed confidence about the chances for victory, saying he has always opted for a primary election, except in 2006, when he won a special election to replace Sean T. Connaughton.

The county Electoral Board’s decision appeared to be partisan, Stewart said.

“Well, I’d like to think that there wasn’t any foul play, but it certainly looks fishy,” he said.

The lawsuit names Prince William’s three Electoral Board members as defendants, plus members of the elections panels in Manassas Park and the city of Manassas, where voters participate in the sheriff’s election. Officials there have yet to decide whether to pursue a primary election.

Victoria St. Martin contributed to this report