LOS ANGELES (Reuters) - Movie stars accustomed to polite rivalry for coveted film roles and Oscar glory are taking sides in an increasingly bitter labor dispute between Hollywood's two actors unions.
The larger and more militant Screen Actors Guild this week enlisted such high-profile members as Jack Nicholson, Ben Stiller and Nick Nolte in its campaign to scuttle a contract negotiated by the American Federation of Television and Radio Artists.
Other A-list performers, including Tom Hanks, Kevin Spacey, Alec Baldwin and Sally Field, who won an Oscar for her role as a sweatshop union organizer in "Norma Rae," sided last week with AFTRA in publicly urging that union's 70,000 members to ratify the labor pact.
The dispute is ratcheting up tensions in Hollywood over the possibility of actors walking off the job this summer, just as the film and TV industry is still recovering from a 14-week writers strike that ended in February.
SAG leaders say AFTRA's tentative labor deal, covering work on prime-time television, is fatally flawed and undercuts SAG's position in its own contract talks with the studios on a broader TV and motion pictures contract.
Both contracts expire on June 30, though SAG leaders say they are prepared to negotiate past that deadline if necessary to get a deal.
Meanwhile, they are going all out to persuade some 40,000 of SAG's 140,000 members who belong to both unions to vote "no" on the proposed AFTRA settlement, and have suggested the two unions could reunite afterward to bargain jointly.
The two had bargained together for nearly three decades, but AFTRA decided to go its own way earlier this year after long-simmering tensions with SAG reached a boiling point.
AFTRA leaders maintain they have negotiated the best deal possible, one they say improves on contracts obtained earlier this year by Hollywood directors and striking screenwriters, and they vow not to go back to the bargaining table with SAG under any circumstances.
The studios, and some union members, have accused SAG leaders of dragging their feet in talks while campaigning to defeat the AFTRA deal, which requires a simple majority of ballots returned by July 8 to win ratification.
An AFTRA spokeswoman said union leaders are "very confident about the merits of the deal."
But they have cast the consequences of a defeat in the most dire terms, saying rejection would likely lead to a strike as SAG seeks to press demands that are otherwise beyond reach.
SAG has argued just the opposite.
"The SAG national negotiating committee knows that a 'no' vote makes a strike less likely because it shows that all actors want a better deal," SAG said in a full-page ad printed on Wednesday in the industry's two leading trade publications, Daily Variety and The Hollywood Reporter.
SAG plans to run similar ads on Thursday, along with the names of 67 members urging a "no vote."
The vote-no campaign also has included recorded telephone messages to dual union members from Ed Asner and Sandra Oh, a mass mailing and video messages posted on SAG's Web site from Martin Sheen, Ed Harris and Viggo Mortensen.
AFTRA, in turn, has collected more than 600 signatures on a petition urging ratification of the deal.