LAS VEGAS, March 2 - In a vote likely to create deeper tensions inside the labor movement, the leaders of the A.F.L.-C.I.O. rejected a proposal on Wednesday to cut in half individual unions' contributions to the federation to free up more money for organizing.
The 15-to-7 vote against the proposal put forward by five large unions came during the federation's winter meeting here, which was taking place under a threat by the A.F.L.-C.I.O.'s largest union, the Service Employees International Union, to leave the organization.
The unions backing the proposal vowed to continue fighting, saying they hoped to secure a majority before the A.F.L.-C.I.O.'s quadrennial convention in July. Several also left open the possibility of a leadership challenge to John J. Sweeney, the federation's president, who has tried unsuccessfully to stem the erosion in organized labor's ranks.
On Tuesday, Mr. Sweeney proposed a cut of 17 percent, or $15 million, in individual unions' contributions, money that the unions would then use for organizing and match on a basis of four to one.
But the five unions argued that a 50 percent cut in contributions was important to get unions to invest more in organizing, to shake up the A.F.L.-C.I.O.'s bureaucracy and to demonstrate a commitment to far-reaching change.
"The current debate is not about dollars," said James P. Hoffa, president of the International Brotherhood of Teamsters. "It is about a vision of the future of the American labor movement."
The Teamsters were the proposal's main sponsor, which was also backed by the service employees, the food and commercial workers, the laborers, and Unite Here, a union representing apparel, hotel and restaurant workers. At the last minute, the United Auto Workers joined in.
At a news conference Andrew Stern, the service employees' president, dodged the question of whether he might still withdraw his 1.7-million-member union from the federation. To improve living standards for workers, Mr. Stern said, the labor movement needed to do all it could to grow and to organize workers.
"What I want to do and what we all want to do," he said, "is restore the strength of workers in our country, and we can't do it by growing smaller. We have to grow stronger."
Unhappy with the A.F.L.-C.I.O.'s bureaucracy and its failure to stop unions from shrinking, Mr. Stern has threaten to secede and create a new workers movement that he hopes would be a catalyst for revitalizing labor. But his threats to withdraw in turn have angered many labor leaders, who call him impulsive and divisive and assert that seceding would hurt labor badly.
"Our greatest strength has always been our unity, our willingness to stick together," said Richard Trumka, the A.F.L.-C.I.O.'s secretary-treasurer. "I promise you one thing: If we stick together, we'll get a solution and grow. If we get fragmented, every part of the fragments will be weaker, and the big losers in that will be American workers."
Mr. Stern and his allies have also called for measures to speed mergers to create larger, stronger unions with clear lines of focus so they do not undercut one other in organizing and negotiating. But his and the Teamsters' proposal to cut contributions to the labor federation have dominated the meeting here, partly because of fears that such a sharp cut, coming to about $40 million a year, would force the A.F.L.-C.I.O. to reduce its staff and its responsibilities.
Mr. Sweeney said he was all for more organizing, but he opposed the 50 percent cut, saying it would weaken the A.F.L.-C.I.O. far too much. He argued it would be wisest for the federation to spend more on political efforts, while individual unions financed organizing efforts, as they have traditionally done.
"My hope is that we're going to be able to move changes that Andy will feel are bold and meaningful," said Mr. Sweeney. "We're also hopeful that we don't lose an affiliate, especially a major affiliate like S.E.I.U."
Mr. Stern has sought to turn the debate over a 50 percent cut into a broader debate over how serious labor leaders are about change. Many of his opponents say unions are already so embattled that it is foolish for Mr. Stern to start a civil war over what percentage to cut contributions.
Mr. Sweeney said he was pushing through sweeping changes, among them a large increase in political and legislative spending, to $45 million a year, so the federation could have a permanent political presence in many states and mount major campaigns simultaneously in national elections and state elections.
A big question at this week's meeting is whether John Wilhelm, the president of Unite Here's hotel and restaurant division, will declare that he is running against Mr. Sweeney. On Wednesday, Mr. Wilhelm hedged, saying labor's focus right now should be setting the A.F.L.-C.I.O.'s goals.
"The question about leadership elections should come after that, not concurrent with it," he said.
Mr. Sweeney has said he has locked up enough support to ensure his re-election to a four-year term.