Environmentalists are described in a new Republican report as members of "fundamentally self-interested" elite leisure class who are "self-motivated to thwart economic development because only they garner the benefits of extremist environmental protection."

The report, prepared by the House Republican Study Committee, says most members of environmental groups are affluent, upper middle class professionals who "stand to gain the most from complete preservation of scenic refuges because only they have the time and money to frequent such retreats."

The groups, the report says, have infiltrated academia, orchestrated the media for their advantage and "fraudulently manipulated the courts in a fashion that legitimizes illegitimate energy advocacy programs and defrauds the goverment and the poor."

"This specter of enviromentalism haunts America by threatening to inhibit natural resource development and economic growth," the report concludes. "Failure to recognize this and to respond accordingly compromises the natural resource development objectives supported by a majority of the American public."

The 13-page report was circulated as an "information service" by the committee, a caucus of Republican conservatives which includes 154 of the party's 192 House members.

It was greeted with some confusion by environmentalists. Many originally dismissed it as a parody.

"It seemed so removed from reality that it appeared to be a work of fiction," says Louise Dunlap, president of the Environmental Policy Center. "It sounded so ridiculous I didn't think it could be true."

Richard B. Dingman, executive director of the study group, says the report was prepared to alert conservatives about the activities of environmentalists. The only unfavorable reaction he has received was a mild reprimand from Rep. Robert E. Badham (R-Calif.), the committee's new chairman. "He told me, 'I think you were a bit too strident in your language,' " Dingman says.

Traditionally, environmental protection has been a bipartisan issue supported by Republican and Democratic presidents and legislators. Many members of environmental groups also are Republicans. But the actions of the Reagan administration have set it increasingly at odds with environmental groups.

The report describes these groups as part of a "minority fringe" dominated by liberal Demcorats out of touch with the public. It says since they failed in "their efforts to isolate Interior Secretary James G. Watt as an environmental madman, environmental organizations are now obligated to attack the entire Reagan administration."

The report debunks environmentalists as altruists and traditional conservationists. It says that "Teddy Roosevelt-styled preservations favored a balanced approach to resource management" while current environmentalists "are intent on locking up natural resources and precluding resource development and economic growth."

The report claims environmentalists, described as members of the "affluent wine and cheese" set, are motivated by their self-interests. "Only they garner the benefits of extremist environmental protection and only they are isolated from the harmful consequences of sluggish economic activity," it says.

The report pictures environmental groups as a dangerous political force with inordinate influence on public policy.

It says they have manipulated allies in the media to get favorable press coverage, funneled legal challenges to friendly federal courts in the District of Columbia and infiltrated academia by establishing an environmental law clinic at the University of Oregon and an institute for resource management at the universities of Washington and Idaho.