The U.S. Chamber of Commerce yesterday stepped up its campaign against a federal consumer protection agency with full-page newspaper ads and a press conference decrying the problems faced by the lobbyists of American business.

In particular, chamber president Richard L. Lesher accused Esther Peterson, President Carter's consumer adviser, of playing dirty in the battle over the legislation.

"There's an old quotation that "hell hath no fury like a woman scorned," Lesher said at the start of a press conference in the chamber's headquarters overlooking Lafayette Park. "Believe me, I know what it means. We can write this today," Lesher advised reporters present, "as the saga of a woman scorned."

Peterson came under attack for a short, indignant speech she made last week before the Women's National Democratic Club in which she charged that "big business is using every tactic money can buy to ensure that consumers are deprived of the same rights of representation in Washington that large companies have long enjoyed."

The bill to create a federal consumer protection agency had just squeaked through the House Government Operations Committee by 22 to 21. The close vote elated the chamber and other opponents who confidently predicted that the bill will be defeated on the House floor.

Lesher was particularly annoyed by a claim in Peterson's prepared text that the chamber had a "lobbying budget" of $20 million in 1975. She compared this with the $15 million a year for the proposed consumer agency, which, she said, "the chamber is fond of calling a 'super agency.'"

"Patently false," said Lesher, who declared that the chamber's total 1975 budget was $11.2 million. "Only a very small fraction of our budget is spent on direct lobbying," he said.

He also assailed what he described as Peterson's "attempt to impugn the character of (former Watergate special prosecutor) Leon Jaworski, a highly qualified and respected constitutional lawyer, by accusing him of misreading the proposed law." Hired by the Business Roundtable for an undisclosed fee, Jaworski sent a four-page letter attacking the bill to all members of the House Government Operations Committee.

A Peterson aide replied yesterday that she did err in stating that the chamber had a budget of $12 million. (The figure actually applied to the combined budgets of the chamber and the National Association of Manufacturers, another principal opponent of the measure.) But she had no apologies for the remarks about Jaworski.

Excepts of the Jaworski letter, but not the paragraph pointing out that he had been retained by the Business Roundtable, were reproduced by the chamber yesterday as part of the a full-page ad in the New York Times headlines, "The Last Thing Consumers Need Is Another Government Agency."

Lesher called it "laughable" to suggest that business interests dominate government decisions.

"The fact is that Congress is dominated by antibusiness, pro-labor forces," Lesher asserted. "We're swimming upstream."