Four national consumer groups have attacked the Federal Communications Commission for failing to ask the American Telephone and Telegraph Co. for a detailed accounting of its $2 million congressional lobbying campaign.

The FCC has no way of knowing whether the phone company is "forcing its customers pay for an anti-consumer lobbying campaign that's against their best interests," charged Gene Kimmelman, an attorney for Congress Watch, the public interest group founded by Ralph Nader.

AT&T has already pledged that its lobbying effort, aimed at blocking a bill that would alter some terms of the phone company's proposed antitrust settlement with the Justice Department, will be funded entirely from shareholders' proceeds and not from its regulated monopoly rate-base.

However, the groups cited a number of tactics in the six-week-old grassroots campaign that they say give the appearance of being funded with ratepayer resources. These include charges that Bell employes sign lobbying petitions and view Bell political films during working hours; that AT&T personnel lobby Congress with letters sent on company stationery using Bell postage meters; and that at least one AT&T local operating company, Mountain Bell, stuffs monthly phone bills with inserts proclaiming the dangers of HR 5158, the bill the company is opposing.

AT&T spokesman Pik Wagner said the company is keeping careful books on all such activities, separating out the lobbying expenses from normal business expenses. "They are available to the FCC whenever they want them," he said.

But Common Cause President Fred Wertheimer complained in a letter to FCC Chairman Mark Fowler last week that the commission should "not have to depend on the goodwill of regulated industries to get this information--it should be mandatory." ive years ago, Common Cause asked the FCC to make mandatory such lobbying disclosures by regulated carriers. The commission has not yet acted on the request. A spokesman for Fowler said last week the matter would be reviewed, but added that he believed the commission's general auditing system was sufficient to monitor Bell's lobbying expenses.

The FCC has taken the position in the past that it is not illegal for lobbying expenses to be included in the rate base as routine operating expenses. However, the spokeman added, the extraordinary lobbying expenses involved in AT&T's current campaign might be viewed differently if ever put to a test.

Joining Congress Watch and Common Cause in the complaint to the FCC were Consumers Union and the Consumer Federation of America.