Fairfax County's business community and political party regulars are urging the Board of Supervisors to abolish voluntary limits on campaign contributions the board adopted seven years ago in an effort to curb the power land developers wielded in county politics.

A task force appointed by the board will report Monday that the limits are unfair, unconstitutional and ineffective. The group reached its position on a 5-to-4 vote, with the Chamber of Commerce and party representatives named by the board outvoting those from the League of Women Voters, the Federation of Citizens Associations and Common Cause.

The voluntary guidelines, far stricter than what Virginia law requires, were in effect during the 1975 and 1979 supervisor elections. In those elections, most candidates pledged to disclose all contributions greater than $15, to reject gifts greater than $500 and to refuse contributions from developers or cable television firms with official business before the board.

The Fairfax Chamber of Commerce always opposed the guidelines, saying they discriminate unfairly against the business community. Members of the Fairfax Republican and Democratic central committees have said the rules hamper fundraising while accomplishing little.

"Let's be honest," Philip M. Reilly, a beer wholesaler and chamber president, said. "If somebody thinks they're going to buy a supervisor, they're not going to do it with a check and they're not going to do it with a couple of hundred dollars."

"No one is saying that any member of the current board should be suspect," responded Lilla D. McC. Richards, president of the Federation of Citizens Associations, who chaired the task force and voted with the minority. "We're trying to maintain a climate where public confidence won't be jeopardized."

State law places no limit on individual or corporate gifts and requires disclosure only of gifts of more than $100. The Fairfax task force found that about 90 percent of the funds raised for representative 1979 supervisor races would not have been disclosed under that standard.

The task force also found that only two current supervisors, Democrats Audrey Moore and Martha V. Pennino, consistently followed the guidelines in 1979, although others promised to do so. Many of the violations were minor or resulted from inadequate understanding of the rules, the task force said.

Three former supervisors and five lawyers and former officials were convicted in the late 1960s of bribery conspiracies in rezoning cases. The supervisors elected in 1971 in the wake of the scandal pledged in 1975 to follow campaign rules stricter than those required by the state, and they urged their opponents to abide by the same rules.

The guidelines were voluntary because Virginia law forbids localities to enact laws stricter than its own without the express approval of the state legislature. James M. Rees, a lawyer and chamber representative on the task force, said the voluntary label cloaks the coercive nature of the rules. "If imperfections exist in the present law, such imperfections must be addressed in the General Assembly," Rees wrote in the report endorsed by a majority of the task force.

Republican Del. Vincent F. Callahan Jr., also a task force member and a senior member of the House Elections Committee, criticized the voluntary nature of the guidelines for a different reason, saying they cannot be enforced. "They should be compulsory or they're not worth the paper they're printed on," Callahan said. "I just wonder how serious they the supervisors are about the whole thing."

Those who favor the voluntary guidelines said the General Assembly is unlikely to approve stricter rules. "Fairfax has a higher standard than the rest of the state," Richards said.

Rees also said it is unconstitutional and unfair to deny developers the same right to participate in politics as everyone else. "Why not single out the teachers or the labor unions?" he said. "The developers are only one side of the land use decisions, and you haven't singled out the other side (such as the environmentalists)."

Moore said developers and their lawyers should be targeted because they remain the most powerful single interest in Fairfax and the one that most depends on board action. Rezonings by the board can make or break a developer--a point Supervisor James M. Scott made last spring in a letter to the task force.

"If, at any time, the public perceives that campaign contributions play even a small role in rezoning and land use plan amendment decisions," Scott wrote, "the public trust, which has been so carefully reconstructed since the rezoning scandals of the mid-'60s, would once again be jeopardized."

During the 1979 campaign, Moore said, developers lobbied to have the rules changed and offered to evade the rules by having different members of their firms each contribute $15, an offer Moore said she declined.

Fairfax political party committees have not taken formal positions on the guidelines. The four party representatives to the task force and other committee members have opposed the rules. "They're not interested in zoning because they're not interested in local government," Moore said of the Democratic and Republican party regulars. "They're interested in electing supervisors because it makes it easier to elect state and national people . . . They don't care who gives the money."