The National Smokers Alliance and Philip Morris USA, the nation's largest cigarette maker, have split over the group's attack on Sen. John McCain (R-Ariz.), a presidential candidate and architect of legislation bitterly opposed by the tobacco industry.

Philip Morris last week declared an end to its substantial financial support of the Alexandria-based alliance, which had filed a complaint with the Senate ethics committee against McCain.

Although the alliance had joined with other tobacco interests in fighting McCain last year, this time Philip Morris said the secretive organization it helped create six years ago had gone too far.

To emphasize its split, the cigarette maker issued a public statement, first reported in Roll Call, denouncing the alliance and praising McCain as "a public servant of the highest integrity and ethical standards."

At issue was a June 22 complaint that lawyers for the alliance filed with the Select Committee on Ethics, accusing McCain of violating the Senate franking privilege by sending a letter about tobacco legislation to potential Republican voters in New Hampshire, Iowa and other states with early GOP presidential contests.

McCain's office denounced the complaint as baseless. Philip Morris, which has funded many of the alliance's multimillion-dollar campaigns for "smokers' rights" in localities across the country, went further.

"Philip Morris does not in any way support or condone the NSA ethics filing," said Ellen Merlo, senior vice president for corporate affairs of Philip Morris USA, in a statement. "In fact, we hereby condemn it."

Thomas Humber, a former Philip Morris public relations executive who has run the alliance for the past five years, said yesterday that his group still believes McCain improperly used taxpayer money "to write what we regard as a political letter." He said his group would press the ethics committee to resolve the issue.

In the meantime, he vowed the alliance would push ahead on its agenda without the cigarette maker's money.

"We've been saying that this organization has been independent from its inception and, if this doesn't prove that, I don't know what will," he said with a laugh. "We're going to keep on going with the resources we have."

Humber conceded that Philip Morris's contributions to the alliance have been "substantial. There is no question about that and there is no question that we will go on." He declined to say what funding sources his group might tap. "I have no interest in providing guidance for my enemies," he said.

Like the industry-funded Tobacco Institute of Washington, which closed earlier this year, the alliance has provoked the ire of anti-tobacco groups. The American Nonsmokers' Rights Foundation, a California group, has charged that the alliance was created by Philip Morris and its public relations firm of Burson-Marsteller in 1993 to fight threats by local government to restrict smoking in public.

Earlier this year, the foundation branded the alliance as "Philip Morris' No. 1 Front Group," claiming that the tobacco giant provided Humber's organization with as much as 96 percent of its funds. While Humber would not discuss those charges, other officials of the alliance have conceded that the industry provides the group with most of its funds.

In addition to Philip Morris, they have cited financial support from Brown & Williamson Tobacco Corp. and Lorillard Inc., two of the country's other major cigarette makers. Records filed with state officials in California indicate that the alliance received more than $42 million from its backers in its first three years of operation, running grass-roots pro-tobacco campaigns in numerous states.

Mark Salter, McCain's administrative assistant, has urged the ethics panel to drop the matter, saying the letter in question was only an effort to report that tobacco lobbyists had spent $56 million last year to defeat the senator's tobacco legislation. Salter said that the 19,008 letters McCain mailed cost taxpayers a total of $5,200.

The mailing was a response to all individuals around the country who had written McCain about the tobacco legislation, Salter told the ethics committee's chief counsel. "Sen. McCain has long had a policy of answering all mail and inquiries he receives," Salter said.

Julia Carol, president of the California nonsmokers group, said the alliance's fate is sealed. "Unless they can find another corporate sugar daddy, they're done," she said.

Once her group had outed the tobacco company as the alliance's principal backer, she said, it would be merely a matter of time before the alliance dies and another group rises to take its place.

CAPTION: Sen. John McCain was accused by the National Smokers Alliance, an industry- funded group, of misusing official mail to comment on tobacco legislation.