A long history of bad blood between the Writers Guild of America and the Intl. Alliance of Theatrical Stage Employees has boiled over.

In a broadside delivered Tuesday, IATSE president Thomas Short has accused the guild’s leadership of incompetence and irrresponsibility for its eight-month delay in contract talks with studios and nets.

In response, WGA West exec director David Young accused Short of caving in to the companies and strikebreaking.

Short’s blast, the latest outburst in a long line of hostilities between the unions, singled out WGA West prexy Patric Verrone for disregarding the impact of the guild’s actions on the 100,000 below-the-line members of IATSE. With studios and networks planning to accelerate production to withstand a work stoppage, a “de facto” strike could then result due to an excess of stockpiled TV shows and features.

“IA working families will not only lose their livelihoods but the work hours necessary to keep them eligible for health insurance, pensions and other IA benefits,” he said in a statement issued Tuesday.

But Young said Short is acting in concert with the AMPTP.

“The ‘de facto’ strike threat is a bogeyman conjured up by the AMPTP to try to intimidate Hollywood unions into giving up their most effective leverage,” Young said. “It is unfortunate that president Short has joined with the AMPTP in using this scare tactic.”

Short said he contacted Verrone on Nov. 28, after it became known that the WGA had spurned an offer to negotiate in January and opted instead for starting around Labor Day, and asked Verrone to reconsider but Verrone refused. Nick Counter, president of the Alliance of Motion Picture & Television Producers, has asserted that after he had agreed with Young to launch negotiations in January, Young withdrew the offer because the WGA board had decided to delay negotiations until the fall.

“The fact that the WGA backed out of their own proposed talks shows their complete and utter disregard for the vast majority of motion picture and television workers in the entertainment industry,” Short said. “A small faction inside the WGA is determined to undermine the health and welfare of an entire industry.”

Over the weekend, Verrone sent Guild members a strongly worded defense of the decision to wait until September, two months before the current contract expires on Halloween, and accused the AMPTP of a litany of misconduct including duplicity, bullying, manipulating public opinion, ignoring history and refusing to negotiate over new technologies.

Young chimed in on Tuesday, asserting that no “de facto” lockout took place in 2004, after the WGA began negotiations less than one month before contract expiration. “We trust that the studios and networks will act responsibly again and not unnecessarily disrupt the work,” he added.

Short locked horns with the WGA and SAG in 2001 under similar circumstances after both unions decided to hold off negotiations until a few months prior to expiration. Both those deals were signed a few days after the contracts expired, leading to a “de facto” strike as companies cut back production due to stockpiling.

Short also noted that IATSE won a federally supervised election Monday to represent about 60 employees at the CW’s “America’s Next Top Model.” The WGA West had attempted to organize the show’s writers, who struck in July over the producers’ refusal to grant jurisdiction to the WGA.

Short said the guild’s organizing efforts were “mishandled due to zero experience at organizing in the entertainment industry” — a slap at Young, whose background is in organizing in the construction and garment industries.

“Top Model” showrunner Ken Mok has asserted that once the writers struck, he created a new system utilizing IATSE editors and eliminated the writing slots. The WGA has filed a complaint with the federal government alleging that Anisa Prods. violated federal labor laws by “terminating, eliminating the positions of and/or refusing to reinstate” the writers.

Young issued a bristling slam at Short’s criticism of the “Top Model” campaign.

“It is ironic that president Short criticizes the WGAW for mishandling the ‘America’s Next Top Model’ campaign,” he said. “The 12 strikers at ‘ANTM’ lost their jobs because of the willingness of Mr. Short to have his union do struck work. This is contrary to the most basic trade union principles in which we believe.”

Short has long criticized what he perceives as the WGA West’s incursions into IATSE turf in animation writing and reality TV — areas in which the WGA West has focused its organizing efforts.

“We are not going to be the javelin catchers for the Writers Guild,” Short said last year. “We’re going to throw a few at them.”

IATSE and the DGA have usually negotiated their contracts far in advance of expiration, contending that a better deal’s available at that point with the companies willing to offer a premium in exchange for labor peace. Verrone and other advocates of going up against a deadline assert that the strategy maximizes a union’s leverage due to the strike threat.