A bitter split within organized labor over control of $20 million earmarked for mobilizing voters is threatening to fracture a broader effort by liberal groups to ally themselves against President Bush's reelection bid in 2004.

The dispute involves the new Partnership for America's Families, a political committee financed with $20 million from unions and as much as $10 million from individual, pro-Democratic donors. The partnership's executive director, Steve Rosenthal, former political director of the AFL-CIO, is pitted against Gerald W. McEntee, president of the American Federation of State, County and Municipal Employees. Also at odds with Rosenthal are leaders of black and Hispanic labor organizations affiliated with the AFL-CIO.

At one level, the battle has become a test of strength within the AFL-CIO between the leaders of two large public employee unions: McEntee of the AFSCME and Andrew L. Stern of the Service Employees International Union, a Rosenthal ally. McEntee and Stern regularly compete to organize government workers, and both are considered possible candidates for the AFL-CIO presidency when incumbent John J. Sweeney retires, although McEntee and Stern say they are not interested in the post.

Sweeney, alarmed by the divisions within the labor movement just as political groups nationwide are beginning to mobilize for next year's election, has met with the key players and hopes to bring them together. "The discussions are very sensitive," Sweeney said. "We have a little bit of work to do."

A fractured trade union movement could, in turn, severely hamper the incipient effort to create an alliance of liberal groups eager to defeat Bush. Labor and Rosenthal's partnership group are viewed as key pillars in the effort, which also includes the Sierra Club, NARAL Pro-Choice America, the NAACP, the Human Rights Campaign, the League of Conservation Voters and EMILY's List.

"We are fighting among ourselves when there is a common enemy, a very strong common enemy," said Harold Ickes, an aide to President Bill Clinton now trying to unite the liberal organizations. "If we start dividing rather than coming together and working together, it's going to redound to the benefit of the Republicans, and to the detriment of the Democrats."

Gina Glantz, a top official at the Service Employees International Union, said the labor disputes have made it "a happy day for the White House. I'm sure they feel their voter suppression efforts have just been enhanced."

The Partnership dispute broke into the open two weeks ago when McEntee, the organization's board chairman, abruptly resigned, along with the other two board members. Under Rosenthal, McEntee said, the partnership "failed to win the support of key labor unions and leaders and other constituency organizations."

Stern defended Rosenthal's leadership, saying the criticisms are "uncalled for, not true. This seems like a very personal effort without any concern for the implications for our members in a presidential election."

The dispute reached new levels of hostility last weekend when a prominent black union leader sharply attacked Rosenthal. William Lucy, secretary-treasurer of the AFSCME and president of the Coalition of Black Trade Unionists (CBTU), an AFL-CIO affiliate, said Rosenthal's oversight of the partnership amounted to "paternalism."

"We have told Mr. Rosenthal and his organization where he could go and what he could do," Lucy said in a press release. The issue "is about who will decide how the black community will be involved in its own politics and whether labor chooses partnership over paternalism."

Lucy's criticisms were echoed by Oscar Sanchez, executive director of the Labor Council for Latin American Advancement (LCLAA), another AFL-CIO affiliate. "What we object to is Mr. Rosenthal, or someone like him, leading the charge," Sanchez said in a prepared statement. "Mr. Rosenthal proved throughout his seven-year tenure as director of the AFL-CIO's political department that he was not sympathetic to the causes of the minority community."

Rosenthal and other labor political operatives are critical of the CBTU's and the LCLAA's political effectiveness, and Rosenthal has been reluctant to give them money for voter mobilization, a number of labor sources said.

Some black and Hispanic political leaders have rallied to Rosenthal's defense. They include Miguel Contreras, executive secretary and treasurer of the Los Angeles County Federation of Labor and an LCLAA board member; Donald Redmond, deputy director of a program that says it has registered 14,000 black and Latino voters with Rosenthal's help; and Donna Brazile, who managed Al Gore's 2000 presidential campaign. "Steve is a remarkable organizer, a great leader, and his program should continue after the politics are worked out." Brazile said.

Rosenthal said Tuesday that he would prefer to stay out of the fray, noting that new organizations are often controversial and subject to "growing pains."

Many Democrats hope the partnership can counter Republican voter turnout strategies that proved successful in 2002 and help fill the void in Democratic turnout efforts caused by new legal restrictions on party fundraising. They also want the partnership to act as a "traffic cop" coordinating liberal groups' voter turnout activities.