HELENA -- Democratic gubernatorial candidate Brian Schweitzer demanded Friday that his Republican opponent, Bob Brown, ask U.S. Sen. Conrad Burns, Gov. Judy Martz and the Montana Republican Party to quit attacking him on Brown's behalf.

Schweitzer said these third-party attacks violate one of the two clean campaign pledges that both men signed. Each candidate submitted a different pledge, vowing not to say mean things about each other, and both candidates signed both pledges.

''We have both agreed that Montanans deserve a campaign in which third-party attacks are not employed or are denounced immediately if they occur," Schweitzer said. ''Montanans are fed up with negative campaigning, and they deserve something better of their public servants, a fair and frank discussion of issues."

Schweitzer said one provision of his clean campaign pledge that Brown signed says that each candidate agrees in good faith to prevent third parties from attacking the opposing candidates. If this request ignored by the third party, the pledge says the candidate who has the most to gain from the attack will immediately criticize the activity and publicly demand that the attacks stop immediately. If they do not cease, the agreement is void.

''Recent events appear to violate our agreement," Schweitzer said. ''Just this week, Senator Burns sent out a fund-raising letter on your behalf attacking me; yesterday, Governor Martz held a press conference attacking me and intentionally misquoting me, while admitting she was acting as part of your campaign; and earlier this morning, the Montana Republican Party sent out an e-mail calling me names."

Schweitzer called on Brown to ask them to cease these attacks immediately and for Brown to make a concerted attempt to prevent further attacks.

Meanwhile, Brown said he signed both pledges on June 9, while Schweitzer apparently didn't sign his pledge until recently.

''It appears to me that he wants to claim that I broke it so he can do whatever he wants to me," Brown said. ''He wants to use this thing as a gimmick. It makes you wonder if he was acting in good faith in the beginning."

Brown said he'll do his best to conduct himself in a way he can be proud of in the race.

''You've got to recognize, too, we've got a First Amendment designed to protect political speech, free speech, and that's fundamental to our freedom," he said. Brown said there's a distinction between this free speech and buying negative political advertising, which is what turns off voters.

''Most reasonable people would think Burns shouldn't be muzzled, Martz shouldn't be muzzled, nor should the Democratic Party when they want to comment about me," Brown said. ''If they are scurrilous, negative type attacks, nobody should do that."

Asked about the negative TV ads, his campaign ran against a Republican primary opponent, Pat Davison, Brown said, ''I felt we needed to respond." Davison had been running negative TV ads against him.

It appears that the clean campaign pledges may already be off, Brown said.

''I'm not going to do anything differently than I ever did before," Brown said. ''I will approach this in a straight forward way. If he tells lies about me, I'm going to tell the truth about him."