The ethics charge filed against Fairfax County Board Chairman John F. Herrity may have harmed his political future, but the continuing debate over relations between county supervisors and developers could hurt other officials in next year's county elections.

That was the assessment of several Fairfax Democratic and Republican political leaders yesterday as they discussed the impact of the criminal charge placed Monday against Herrity, the county's leading Republican officeholder.

"It's not going to do us any good," said Fairfax County Republican Party Chairman James D. Swinson.

"Obviously this is not a plus for Jack," said state Sen. Richard L. Saslaw, a Fairfax Democrat. "It's not the kind of position any politician wants to be in."

Herrity, who is in his 10th year as the county's top elected official, is to stand trial on the misdemeanor charge Aug. 21 in Fairfax County General District Court. If convicted of violating the Virginia public disclosure law, he could be sentenced to a year in jail and fined $1,000.

Herrity has said he is innocent and will fight the assertion by prosecutor Robert F. Horan Jr. that Herrity knowingly violated the law last winter by participating in a controversial land use case without disclosing that he was a business partner of the developer.

In moving against Herrity, Horan, a Democrat, dashed the hopes of some county officials that the sensitive and increasingly publicized question of government ethics would go away.

Several Republicans said that the ethics issue could cut across party lines because of reports, published by the Journal newspapers, that board members Martha V. Pennino (D-Centreville) and Joseph Alexander (D-Lee) have voted on a few land use cases without disclosing their receipt of campaign donations from the applicants.

"The whole board seems to be tarred with this thing, so I think it will be a wash," said state Del. Vincent F. Callahan Jr., the county's senior Republican legislator. "I think it creates an image problem for the board itself."

The Journals said that all members of the Fairfax board except Supervisor Audrey Moore and former supervisor James M. Scott had failed on at least one occasion to disclose a campaign donation from a land use applicant, as required by the law.

Herrity's seat and all eight others on the county board will be up for election in the November 1987 balloting, and Callahan said that although the charge will cut into Herrity's base of support, "I don't think he's in danger of losing the election. I think he'll win going away."

Others, including Moore, an Annandale Democrat who has been a longtime critic of Herrity, said it was premature to measure the impact of a case that has yet to be resolved in the courts.

Moore noted that Herrity would not be up for election for 16 months. "Sixteen months is a long time in a county where people have short memories," she said. "It's going to depend on how people see this thing and whether they remember it a year from now."

"Nobody knows" how much political damage will be done, said GOP Supervisor Thomas M. Davis of Mason district, who many Republicans say is Herrity's most likely successor. "It's just too early to say."

Several supervisors said yesterday that they were caught off guard by Horan's decision to prosecute. They said they learned of it from Herrity, who was summoned from a closed-door meeting of the supervisors Monday afternoon to accept the warrant.

"Surprised? Of course I was," said Davis. "So was everyone else."

"I think everybody was sort of floored," said Moore. "You don't expect a police officer showing up to serve a warrant on the board chairman."

The issue of ties to developers is a sensitive political issue in Fairfax. Democrats seized upon the issue in last week's special election for the Providence district supervisor's seat. Katherine K. Hanley scored an easy victory over Republican state Del. Stephen E. Gordy, stressing the theme that the Republicans represent the interests of developers.

County Democratic Party Chairman Harris Miller said yesterday that the charge against Herrity strengthens his party's use of that issue. "I think there's a real perception out there that the two parties seem to have different stances on special interests," Miller said.