Mayor Marion Barry, stung by mounting criticism of his veto of a bill giving the D.C. people's counsel more authority to spend money representing consumers in utility cases, described as "B.S." yesterday charges that his action is anticonsumer.

Barry defended his overall record on consumer affairs, but City Council members and civic groups that backed the legislation insist that they were double-crossed and that the mayor bowed to last-minute pressure from the Public Service Commission (PSC) and utility companies.

The PSC and the utilities have tried for years to minimize the financial wherewithal and power of the people's counsel to oppose major rate increases of the gas, electric and telephone companies.

Supporters of the bill say consumers would pay higher utility rates without the bill.

"One of the things I resent most is that we bent over backward to accommodate the executive," said council member Betty Ann Kane (D-At Large), chief sponsor of the bill. "And we resent the PSC, which refuses to come before my committee to explain its decisions in rate cases, going around behind our backs using staff all weekend to lobby council members."

A motion to override the veto may be brought up at today's City Council meeting. Kane and Charlene Drew Jarvis (D-Ward 4) predicted yesterday that supporters of the bill can muster the two-thirds vote necessary for an override, while other members said the vote would be extremely close.

PSC Chairman Patricia Worthy visited the offices of council members yesterday doing last-minute lobbying in support of the mayor's veto, council members said. Meanwhile, two major civic groups distributed a joint letter to council members urging them to override the veto.

The legislation would enable the people's counsel to incur costs for outside legal and technical assistance and to assess the utilities for those costs without the PSC being able to deny the assessments. At present, the PSC has the authority to limit those assessments.

The people's counsel has been operating under special council-passed legislation that will expire in February. Unless the council overrides the mayor's veto or approves different legislation acceptable to the mayor, the people's counsel could no longer hire outside lawyers using assessments on utilities, in light of an adverse ruling by the D.C. Court of Appeals on April 12.

The people's counsel has an annual budget of $825,000 and employs 14 workers. However, from October 1982 through 1983, the office assessed utility companies $2.1 million to pay for outside consultants. The PSC's costs -- an annual budget of $2.4 million, and assessments from October 1982 through 1983 of $2.6 million -- also are borne by the utilities, which in turn pass them on to consumers.

In vetoing the bill last Friday, Barry cited the PSC's unanimous opposition to a provision that would prohibit the commission's paid staff from continuing to take formal positions on proposed rate increases. Critics of this practice say that PSC staff should remain neutral and leave it to the utilities and the people's counsel to argue the merits of proposed increases.

Clarke and others contend that the mayor seized on the dispute over the role of the staff as an excuse for rejecting the entire bill.

"I just don't perceive that amendment as crucial as Barry and the others do," Clarke said. "That amendment was a coat hanger to go after the whole thing."

However, Barry, who met with the three PSC members the day before Thanksgiving, said he was persuaded that it was imperative that the staff continue to provide the commissioners with formal recommendations in rate cases.

"We were concerned about the loss of staff support," said Commissioner Wesley Long, who took part in the meeting with the mayor.

" . . . I think it's extremely important from my position to have it, and I have depended upon it from time to time," Long said.

During an interview yesterday, Barry said that the PSC's arguments were decisive and that he didn't discuss the issue with officials of the major utilities before making his final decision.

"Legally, I have a responsibility to express my concern, and the way you do it is through the veto," Barry said.

Barry noted that the D.C. Court of Appeals has upheld the PSC in eight of the 10 challenges to the commission's rulings since 1979 and called this "an outstanding record."

Some of those who disagree with allowing the PSC staff to continue to take formal positions in rate cases contend that the staff has frequently sided with the utilities.

The D.C. Federation of Citizens Associations and the Federation of Civic Associations issued a joint resolution yesterday urging an override of the veto.

"I've had a lot of calls" from citizens and advisory neighborhood commissioners, said council member Polly Shackleton (D-Ward 3), who said she is supporting an override. The mayor "had plenty of opportunity to work with everyone on it the bill ," she said.

Senior citizens supported the bill as approved by the City Council and "many, many seniors have called me on the phone," said Juanita Thornton, chairman of the mayor's commission on aging.

Frederick D. Dorsey, the people's counsel, declined to comment further on the controversy yesterday. Last Friday, Dorsey issued a statement saying he was "gravely disappointed" by Barry's veto. "The impact of this veto on all consumers everywhere cannot be overstated."