The future of the big-budget “The Hobbit” movies — already caught in MGM’s financial morass — became more uncertain Sunday when Peter Jackson threatened to move the twin productions from New Zealand in a dispute with several actors’ unions.

Jackson, who is exec producing and writing “The Hobbit” and may direct the films, said if he is forced to move the productions, other studios will steer clear of the country, which could “look forward to a long, dry, big-budget movie drought.”

“Warners would take afinancial hit that would cause other studios to steer clear of New Zealand,” Jackson declared in a statement.

Dispute flared Friday when seven major actors’ unions told members not to work on “The Hobbit” because producers refused to sign a deal with local performers. “If you are contacted to be engaged on ‘The Hobbit,’ please notify your union immediately,” the unions said.

Jackson, insisted Sunday that he’s not anti-union, although most of his statement was devoted to villainizing the Australian actors’ union the Media Entertainment & Arts Alliance as greedy and accusing it of plotting to ruin New Zealand’s reputation as a film location. The Australian union established a New Zealand branch in 2006.

“There is a twisted logic to seeing NZ humiliated on the world stage, by losing ‘The Hobbit’ to Eastern Europe,” Jackson said.

Co-financers MGM and New Line had no comment. But the dispute adds another potential roadblock to the rocky road already traversed by “The Hobbit.”

The films have not been greenlit and lost director, Guillermo del Toro, in May. He pointed to the uncertainty surrounding MGM’s future as his reason for bowing out. New Line has insisted all along that MGM’s financial problems were not the cause of the delays.

The boycott is organized by the Intl. Federation of Actors, of which the unions are members, to support the New Zealand actors. The unions asserted that those performers — repped through the Australian actors union — have been working under contracts without minimum guarantees of wages or working conditions, residual payments or cancellation payments.

“All unions remain hopeful that this situation can be resolved with goodwill on all sides,” the group said.

But Jackson repeatedly blistered the Australian union, asserting that the New Zealand branch isn’t a union and estimating that it reps a “tiny minority” of local actors, which he put at 200 of 2,000.

“I can’t see beyond the ugly spectre of an Australian bully-boy using what he perceives as his weak Kiwi cousins to gain a foothold in this country’s film industry,” Jackson said. “They want greater membership, since they get to increase their bank balance.”

Jackson accused MEAA of “endangering” a project that hundreds of people have worked on for two years, and the thousands about to be employed for the next four years, asserting its demands can’t be met and are unlawful.

The unions have said that the accusation of illegality is nonsense. “The Alliance has obtained legal advice that there are a variety of lawful means which could be used to establish the minimum wages, working conditions and residuals for performers on the production,” they said in a statement distributed Friday.

Aside from MEAA, the unions supporting the boycott are Canadian Actors Equity, U.S. Actors Equity, the Screen Actors Guild, U.K. Actors Equity, the American Federation of Television and Radio Artists, and the Alliance of Canadian Cinema, Television and Radio Artists.

Jackson also took a shot at SAG, saying it’s supporting MEAA because it would benefit from studios having a “miserable” experience in Australia/New Zealand. SAG had no immediate response.

“It sure feels like we are being attacked simply because we are a big fat juicy target — not for any wrongdoing,” Jackson added. “We haven’t even been greenlit yet! It feels as if we have a large Aussie cousin kicking sand in our eyes … or to put it another way, opportunists exploiting our film for their own political gain.”

“Hobbit” has long been viewed as a potentially lucrative successor to Jackson’s adaptation of JRR Tolkien’s “The Lord of the Rings” trilogy. Project was tied up twice by lawsuits over “Rings” profits, once by Jackson and once by Tolkien’s heirs, settled in 2007 and 2009.

Del Toro, who committed to direct “The Hobbit” pics in 2008, said in May that sets, wardrobe, animatics and battles sequences had all been fully prepared.

The admonition by the unions to their members doesn’t prevent actors from working on “The Hobbit” but puts them on notice that they could be punished if they do so.