Breaking sharply with the enforced harmony of the Democratic National Convention, the president of the largest AFL-CIO union said Monday that both organized labor and the Democratic Party might be better off in the long run if Sen. John F. Kerry loses the election.

Andrew L. Stern, the head of the 1.6 million-member Service Employees International Union (SEIU), said in an interview with The Washington Post that both the party and its longtime ally, the labor movement, are "in deep crisis," devoid of new ideas and working with archaic structures.

Stern argued that another four years of Bush administration policies might be less damaging than the stifling of needed reform within the party and the labor movement that he said would occur if Kerry becomes president. He said he still believes that Kerry overall would make a better president than President Bush, and his union has poured huge resources into that effort. But he contends that Kerry's election would have the effect of slowing the "evolution" of the dialogue within the party.

Asked whether if Kerry became president it would help or hurt those internal party deliberations, Stern said, "I think it hurts."

Stern's dissatisfaction with the AFL-CIO and the Democratic Party is not new, but his decision to voice his frustration on the opening day of a carefully scripted convention was an unwelcome surprise to Kerry's convention managers, who had been proclaiming their delight at the absence of any internal conflicts.

Speaking of the effort to create new political and union organizations, Stern said, "I don't know if it would survive with a Democratic president," because Kerry, like former president Bill Clinton, would use the party for his own political benefit and labor leaders would become partners of the new establishment.

"It is a hollow party," Stern said, adding that "if John Kerry becomes president, it hurts" chances of reforming the Democrats and organized labor.

Stern is perhaps the most outspoken of the leaders of four or five unions that have been talking about breaking away from the AFL-CIO to form some kind of new workers movement.

In the struggle for the Democratic nomination last winter, Stern's union, along with the American Federation of State, County and Municipal Employees (AFSCME), delivered an early endorsement to former Vermont governor Howard H. Dean -- a step that solidified Dean's status as the early favorite for the nomination.

Later in the day, AFL-CIO President John J. Sweeney told The Post that Stern's attitude "is not justified." Sweeney, also a product of the SEIU, the largest and fastest-growing union in the AFL-CIO, said the process of change is already underway within labor, adding that he is impressed with "the unity and solidarity" of Democratic support for Kerry. "I'm optimistic about the future of the Democratic Party," he said.

Stern made it clear that his complaints long preceded Kerry's nomination. He said that when Clinton was president, he demonstrated how little he cared for the Democratic Party. Calling the former president "the greatest fundraiser of his time," Stern asked: "If you think the Democratic Party is valuable, why would you leave it bankrupt?" Other elected officials are equally indifferent to the party, he said, adding that if Kerry is elected "he would smother" any effort to give it more intellectual heft and organizational muscle.

The SEIU, representing health care and nursing home workers, state and local employees and janitors among its 1.6 million members, is part of a coalition of liberal, feminist and environmental organizations working in an alliance called Americans Coming Together. ACT has raised more than $85 million, according to fundraiser Harold Ickes, and hopes to reach $130 million by November. Most of the money is being spent in targeted areas to register and turn out the vote of people believed to be likely to support Kerry.

Stern said the SEIU has put about $65 million in union resources into efforts to elect Kerry and other worker-friendly Democrats, the bulk of it directly aimed at labor efforts in behalf of the senator from Massachusetts.

But Stern complained that motivating blue-collar families who have not voted in the past is being impeded because Kerry and the Democrats have declined to address what he calls "the Wal-Mart economy," a system in which he says employers deliberately keep wages so low and hours so short that workers are forced to turn to state Medicaid programs for their families' health care.

He also criticized what he called the vagueness of the Democratic platform on trade issues.

Sweeney said he thinks both complaints are off base. He said Kerry has offered a very specific health plan with real benefits for working families.

And he said he is confident that, despite his history as a supporter of liberal trade agreements, Kerry is sincere in promising to include "core labor standards" in future negotiations.

Stern also said he is not interested in trying to succeed Sweeney as the head of the AFL-CIO but left the door open to leading a breakaway effort.

He said he is convinced from his experience in the civil rights movement that "pressure is needed" to bring about real change. "It was not enough to have Martin Luther King Jr.," Stern said. "You needed Stokely Carmichael" to raise the threat of disruption unless demands were met. Carmichael was the flamboyant civil rights activist known for coining the term "black power."

Stern is perhaps the most outspoken member of the New Unity Partnership, an alliance of the SEIU, the Laborers' International Union of North America, the Hotel Employees and Restaurant Employees International Union, UNITE, and the United Brotherhood of Carpenters. All but the carpenters union are part of the AFL-CIO.

The partnership has repeatedly warned that declining union membership threatens the viability of organized labor, especially in the private sector, which has seen a steady decline in union workers.

On June 21, during the SEIU's convention in San Francisco , Stern caused a stir throughout organized labor by declaring: "Our employers have changed, our industries have changed, and the world has certainly changed, but the labor movement's structure and culture have sadly stayed the same."

Union activists must "either transform the AFL-CIO or build something stronger that can really change workers' lives," he said.

Staff writer Thomas B. Edsall contributed to this report.