The House-Senate conference on the clean air bill erupted in a shouting match yesterday, with the two sides exchanging charges of bad faith and blaming each other for delays that threaten the chances of passing the legislation before Congress adjourns next month.

Sen. Max Baucus (D-Mont.), the conference chairman, called the latest House offer to resolve a dispute on auto pollution "so unacceptable to the Senate it doesn't even serve as a basis for further discussion," and accused House conferees of wasting 11 days to formulate the proposal while the two sides are "still miles apart on key issues."

Rep. John D. Dingell (D-Mich.), head of the House delegation, shot back that conferees would be better served by negotiating rather than "making Bull Run speeches" and engaging in "constant harping."

With the two sides glowering at each other across the long dais of the House Energy and Commerce Committee room, prospects for a new clean air bill seemed the dimmest of any time since President Bush proposed legislation 14 months ago in the hope of breaking a decade-long deadlock on the complex, politically sensitive issue.

Tempers eventually cooled, and another meeting was scheduled for Tuesday. But the dispute reflected the distance each side must travel to conclude an agreement in the final two or three weeks of the session.

Since they began negotiating July 13, conferees have managed to resolve only a handful of the least controversial issues, leaving smog, acid rain and airborne toxics for the final days of debate. Each bill incorporates a special blend of political and industry trade-offs, complicating settlement.

With resolution seemingly far off yesterday, Sen. John H. Chafee (R-R.I.) became the first conferee publicly to raise the possibility of failing to reach accord.

"I'm very distressed by the lack of progress," he told the conference. "I feel what is going on here is a delaying strategy. I worry that we're going to be put in a take it or leave it position. I'd rather come back and vote on it next year."

Yesterday's squabble was touched off by the latest House offer on controls of smog-generating autos. The issue is considered one of the most explosive because of the conflicting interests represented by Dingell, champion of the auto industry in his Detroit district, and Senate conferees committed to cleaning up smog in the 100 cities with excessive levels of the dangerous irritant.

The Senate initiated the process with a proposal 11 days earlier in which it dropped sections of its bill. When it finally responded Wednesday, Dingell's side rejected every Senate proposal except the ones that were concessions. The House offer even appeared to weaken a provision backed by the House that would require ultra-clean fuels for new cars.

The House offer appeared to set up obstacles for other states to adopt the tough air pollution requirements put in place by California, a proposal that was denounced by environmentalists and state officials.

The criticism was especially troubling for Rep. Henry A. Waxman (D-Calif.), the House's leading environmental spokesman, whose district in Los Angeles is the nation's smoggiest. Waxman, a member of the conference, negotiated an agreement with Dingell during committee mark-ups and worked with him to produce the latest House offer.

Defending the proposal yesterday, Waxman said it was stronger in many respects than the Senate's proposed compromise. He accused Baucus and his colleagues of being "misinformed" by pressure groups and failing to read the House offer themselves.

"Don't take my word for it, come in and test drive it," Waxman said of his proposal. "At least have your staff go over it and not dismiss it out of hand."