Unless someone pulls a last-minute rabbit out of an eleventh-hour hat, the biennial convention of the AFL-CIO, which begins on Monday in Chicago, will be radically smaller than originally planned. As things now stand, the four dissident unions that have raised the specter of disaffiliation from the labor federation will announce over the weekend that they won't be attending the convention.

The soon-to-be-MIA unions constitute about 30 percent of the federation's membership. They include three of the AFL-CIO's four largest affiliates -- the Service Employees International Union, the Teamsters, the United Food and Commercial Workers International Union and UNITE HERE, which represents clothing and hotel workers.

For months the leaders of these unions have been meeting with AFL-CIO President John Sweeney and some of his supporters in an attempt to iron out their differences. But the discussions, says UNITE HERE President Bruce Raynor, "have yielded no agreement. There are still sharply different views of the future of the labor movement."

Raynor's assessment is sharply at odds with that of AFL-CIO chief of staff Robert Welsh, who, in a memo he sent to AFL-CIO staff last Monday, predicted that "issues where there are disagreements now will be negotiated and compromise solutions will be found." But it's hard to see the basis for Welsh's optimism.

The dissident unions are calling on the federation to reshape the labor movement into an organizing machine, subordinating the autonomy of the affiliates -- many of which do little if any organizing -- and increasing the authority of the AFL-CIO to mandate coordinated organizing and bargaining campaigns. Their perspective is strongly opposed by a number of other union leaders, particularly those heading manufacturing unions whose numbers have dwindled as their members' jobs have been outsourced and automated. In a recent blog posting, United Steelworkers of America President Leo Gerard took issue with the dissidents' argument that "the real challenge undermining labor's struggles is behavioral" -- that is, the reluctance of some unions to organize. He singled out instead the nation's trade policies and the weakening of the laws protecting workers' rights as the source of labor's woes.

The other sticking point in the deliberations is the continued tenure of Sweeney as AFL-CIO president. It's a somewhat ironic development, as Sweeney hardly comes across as a polarizing figure. But it's precisely his insistence on seeking consensus among his fellow labor leaders that drives the dissidents crazy. In their view, just when the AFL-CIO needs to be demanding more organizing from its affiliates, Sweeney shies from making the changes that would enable the federation to make such demands.

The dissidents can count, and know that they can't win any of their points at the Chicago convention. "What's the point of going when clearly there's a majority that feels that they don't want to make fundamental changes?" one dissident leader asks. "We don't want to fight with them. Why have a big fight?"

By their non-attendance, the dissidents move one step closer to leaving the federation altogether. Conventions are the occasion when unions pay their back dues to the AFL-CIO so they can have full voting strength. Now a sizable chunk of those dues may well go unpaid, further straining a strained relationship. Their absence will also surely anger many of their peers. The convention may be less contentious for it, but it will be no less bitter.

Some dissident leaders hope that their absence will not just anger their colleagues but will alarm them into reaching some kind of settlement. "I think if we can shake things up and make things happen, there will ultimately be a reconciliation," one dissident leader says. But others suggest that the inability to find common ground, particularly on the Sweeney question, will thwart any efforts to hold the federation together. There's plenty of speculation in union headquarters these days about a scenario under which Sweeney wins reelection and then resigns in mid-term, to be succeeded by a successor agreed on by all sides. Whether such a person exists, however, is not at all clear. "It would be hard at this point to identify a consensus successor," says one union president. "So I think we end up with a split."

That's a prospect that leaves Democratic politicos understandably nervous. At her weekly news conference last Thursday, House Democratic leader Nancy Pelosi expressed the hope that the two sides "can resolve their difficulties." In fact, the two sides in this controversy share a fundamentally liberal Democratic orientation, but that won't suffice to keep them together. More and more, says one person close to the dissident leaders, "people are now emotionally and psychologically at peace with the idea of disaffiliating from the AFL-CIO. That's a big thing."

It surely is.