With the Writers Guild of America talking strike, the WGA’s now on a collision course with the Intl. Alliance of Theatrical Stage Employees.

In a missive sent Thursday, IATSE topper Thomas Short blasted the guild over its plan to bar WGA members from penning animated features if there’s a strike. Short, who’s tangled with the guild in the past, pledged he’ll see the WGA — and its leaders — in court since feature animation writing is IATSE’s turf.

“If the WGAW follows through with the threat, the IATSE is prepared to take legal action against the individuals and institutions involved,” Short said in the letter to WGA West president Patric Verrone.

Short’s vituperative response referred to the writers union as “the house of hate commonly known as the Writers Guild of America West.”

Verrone was unapologetic in response, asserting that the guild’s simply trying to protect its own members by barring them from writing during a strike.

“Members of the Writers Guild write the overwhelming majority of animated feature films,” he said in a statement. “We will not allow the employers to take advantage of our writers to produce this work during a strike. Honoring picket lines is a fundamental trade union principle.”

Short’s blast came with the WGA winding up its ninth day of face-to-face bargaining with the Alliance of Motion Picture & Television Producers. Talks recessed in mid-afternoon with both sides agreeing to meet again Tuesday and AMPTP president Nick Counter accusing the WGA of duplicity while admitting that negotiations are going nowhere fast.

“The two sides are fundamentally apart as to what data is truly relevant to the negotiations dealing with productions covered by the WGA agreement and produced by signatory production companies,” he said. “Just as in 2004, the guild has raised a number of red herrings and irrelevant financial information. We believe they should focus on trying to reach an agreement with the production companies represented at the bargaining table.”

The WGA’s end-of-the-day response was equally snarky, accusing the companies of stalling.

“As we move toward our contract expiration on Oct. 31, we look forward to a serious discussion with the companies,” the guild said. “There are a number of important issues that must be dealt with, including homevideo, new media and jurisdiction. So far the AMPTP has not been serious.”

With no progress reported at the bargaining table, and the guild in the midst of taking a strike authorization vote, pessimism’s growing that the WGA will strike soon after the Oct. 31 contract expiration.

And the WGA’s strike rules, posted Thursday on its website, declare that writers can’t work or negotiate for animated features — even though that realm is not under WGA jurisdiction. Nearly all feature animation writing is performed under contracts covered by the Animation Guild, which operates as Local 839 of IATSE.

“Writers are advised to consult with staff at the guild’s strike headquarters to determine the extent to which animation writing is permitted or prohibited before performing any services in order to avoid possible disciplinary action,” the WGA regulation notes. “Members should assume that projects combining live action and animation and live action-based processes, such as motion capture, are covered by this rule.”

The strike rules don’t address whether guild members can perform work if they’ve previously signed Animation Guild deals. Discipline for violation of the strike rules can include expulsion, suspension, fines and censure.

Short noted in the letter that the Animation Guild has represented animation writers for 55 years. “I consider it outrageous for the WGAW to consider violating trade union principles by taking action against individuals performing services under the jurisdiction of another union,” he said.

Short took issue with the WGA late last year over its strategy of delaying contract talks with studios and nets, asserting that a similar approach in 2001 — when the WGA negotiated past the contract deadline — caused a sharp dropoff or “de facto” strike in the subsequent months. WGA leaders have derided the impact of stockpiling, but IATSE (which has over 100,000 below-the-line members) noted Thursday that production has ramped up in recent months through extra episodes of series and a larger-than-usual number of features.

Relations between the two unions have been dismal for many years, with hostilities over such issues as which should have jurisdiction over writers on reality shows and animation. At one point last year, WGA West exec David Young accused Short of being a shill for the companies and using strikebreaking tactics to prevent the WGA from organizing the CW reality skein “America’s Next Top Model.”

The WGA’s other strike rules include bans on any guild-covered work in features and TV and prohibit any writing for new media including Internet and cell phones — even though it’s not yet certain whether the WGA has jurisdiction in that area. Showrunners on TV series will be prohibited from any writing but may be allowed to perform nonwriting services if cleared with the WGA.

Members are also being told that they can’t deliver any material to a struck company or sign or deliver documents relating to writing assignments. And they must honor guild picket lines, perform assigned strike support duties and report strike-breaking activity.

The rules also assert that nonmembers who perform banned work during a strike will be barred from joining the WGA. The guild noted that it can’t discipline nonmembers for “strikebreaking and/or scab writing.”

“This policy has been strictly enforced in the past and has resulted in convincing many would-be strikebreakers to refrain from seriously harming the guild and its members during a strike,” it added.

The last WGA strike took place in 1988 and lasted 22 weeks.