A coalition of labor and consumer groups yesterday opened an attack on big business in an unprecedented effort to unite disparate groups against the basic policy-making methods of corporate America.

In a series of speeches and rallies termed Big Business Day here and around the country, labor and consumer activists issued a call for congressional enactment of legislation that would open corporate boards to public membership and change the rules under which large corporations, operate.

"For the first time in my memory, the consumer movement, the labor movement and the progressive movement have come together for this day," civil rights leader James Farmer said at a rally on Capitol Hill.

The day was filled with attacks on corporate activities -- repeatedly called "criminal" -- such as the poisoning of lands surrounding the Love Canal in New York, and charges that corporations, rather than the public at large, are dictating national economic policy.

Business groups and their supporters, on the other hand, countered Big Business Day by holding their own seminars releasing their own statements.

These groups, such as a "Growth Day" coalition, used the day to extoll what they view as the virtues of corporations and the problems for business brought about by government regulation.

Ralph Nader, an organizer of Big Business Day, called on large corporations to "start obeying the law and raise their own horizons to bring into their councils of judgement value systems notdominated so completely by the almighty dollar."

Rep. Benjamin Rosenthal (D-N.Y.), chairman of a House consumer subcommittee, called on members of the Big Business coalition to "speak to the everyday needs of the people" in pushing for passage of the Corporate Democracy Act, the legislation at the heart of the campaign. Rosenthal is the bill's chief sponsor.

"Your efforts will be portrayed by threats to economic stability and jobs," Rosenthal told a morning rally."Corporations will be doing their best to convince the public that corporate democracy is a threat to them.

"The truth is that you are not as strong as your ideas," he said, noting that he sees the American public as "insecure about the future (but) ready to listen to reasonable talk" about economic change.

The day-long program repeatedly hammered home the theme that large corporations and their Washington lobbying arms have been utilizing current economic hardships to roll back regulations and get the federal government to bail out troubled corporations.

Repeatedly cited in speeches here were congressional efforts to cut back the powers of the Federal Trade Commission, the Occupational Safety and Health Administration and the Environmental Protection Administration.

The sponsors of the event -- calling themselves the Americans Concerned about Corporate Power and led by Nader, Farmer, union leaders Douglas A. Fraser and William H. Wynn, economist John Kenneth Galbraith and Democratic activist Patsy Mink -- also set up a "Corporate Hall of Shame," with exhibits concerning the activities of 11 large corporations.

"Shadow boards," which the group's leaders hope will provide lasting monitoring of the activities of those 11 companies, were set up under the leadership of activists and labor organizers with direct involvement in the specific firms or that sector of the economy.

Organizers and supporters of the day emphasized it will be unable to evaluate the effectiveness of the day's events for at least six months.