The Republican Party in Fairfax County called yesterday for a federal investigation of three School Board candidates for alleged violations of the 1939 Hatch Act, which limits federal employees' participation in partisan politics.

In a letter to the U.S. Office of Special Counsel, Joseph P. Underwood, chairman of the county's Republican Committee, charged that candidates Mark H. Emery, Robert Gardner and Stuart Gibson violated the act by "accepting and actively promoting the endorsement of the Fairfax County Democratic Committee." The letter seeks an immediate investigation.

Emery, a physicist at the Naval Research Laboratory who already holds an at-large seat on the board; Gibson, a Justice Department lawyer seeking reelection as the Hunter Mill representative; and Gardner, an INS official running for an at-large slot, all denied violating the Hatch Act. They noted that School Board positions are nonpartisan and said the Republicans are trying to divert attention from education issues.

Gibson said he was advised by his department's ethics officer that accepting the Democratic Party's endorsement would not violate the Hatch Act.

Although School Board candidates in Virginia are listed on the ballot without party affiliation, many run with party endorsement. In Fairfax, 22 of 24 candidates in the Nov. 2 elections are supported by one of the two major parties.

Underwood, a former Hatch Act counsel in the Department of Health and Human Services, said he recently advised a Republican federal employee to run as an independent to avoid violating the Hatch Act. "He walked away from seeking his party's endorsement, which is what these other three should have done," Underwood said. "The law was made for everybody to obey, not just Republicans."

In his letter to Karen Dalheim in the special counsel's office, Underwood cited an advisory opinion she issued in June on a federal employee's candidacy for the Fairfax board. Federal employees "may become candidates in nonpartisan elections," the opinion said. However, "if the employee solicits the endorsement of a partisan group" or presents himself as a member of such a group in campaign literature or uses party resources, "it is possible to transform an independent candidacy into a partisan one in violation of the Hatch Act. No violation would occur where the party's involvement in the campaign is unsolicited."

Underwood alleges that two of the three candidates in question "actively sought" Democratic endorsement this year. Appended to his letter were campaign materials, including a Democratic Party flier that says "Meet the Hunter Mill Democratic Team" and urges support for Gibson, Emery and Gardner.

"No attempts apparently have been made by any of these candidates to actively disavow the Democrat endorsement," Underwood wrote. "Rather, they appear to take considerable pride" in it.

Dalheim said she could not comment on the request for an investigation. But she said parties "have every right" to endorse candidates, and candidates are not required to disavow endorsements. Problems arise if federal employees seek party endorsements or campaign as partisan candidates, she said.

Emery denied seeking the Democratic endorsement but said he accepted it along with other endorsements. "I am not running as a Democrat," he said. "This is really a smoke screen to pull the discussion away from education."

Gardner said he has been "very careful" to keep his campaign literature "as nonpartisan as possible."

"My activity is well within the requirements of the Hatch Act," he said. "I'm trying to focus on the needs of our children."

Gibson said, "It's a shame that someone would try to prohibit federal employees from advocating on behalf of our children."