UPDATED, 8:25 PM: Neil Patrick Harris took to Twitter tonight to assuage the WGA East’s fears that his upcoming NBC variety might employ nonunion writers:

Know this: my variety show will absolutely be crafted by union writers. I've been assured by ITV that it will be a WGA show. Period. — Neil Patrick Harris (@ActuallyNPH) November 5, 2014

No reaction yet from the WGAE or series producer ITV Studios America.

PREVIOUSLY, 2:51 PM: After he hosts the Oscars in February, Neil Patrick Harris might have to cross a picket line to get to his next gig. The WGA East is threatening to strike the NBC variety show he will host next year unless its producers sign a guild contract. And if it comes to a strike, Harris’ all-around-good-guy image could take a drubbing because he’s one of the show’s executive producers.

NBC last week ordered 10 episodes of the variety show based on Britain’s popular Saturday Night Takeaway. Trouble is, it will be produced by ITV Studios America, which hasn’t signed a contract with the guild and has been locked in a bitter labor dispute with the union over reality shows it produces in the U.S. Unfortunately for Harris, he has walked into a long-running fight: The guild has been trying to get a contract with ITV for its American reality shows for more than four years, and in June it accused the company of working its nonunion writers and producers in “sweatshop conditions.”

Related: WGA East Charges Reality-TV Producers With Creating “Sweatshop” Conditions For A “Beleaguered And Exhausted Workforce”

In a letter sent Friday to ITV executives, WGA East Executive Director Lowell Peterson said that he is “puzzled that ITV apparently intends to produce the show” with nonunion writers and producers. “We have already alerted our many hundreds of comedy-variety members to the fact that ITV is fighting the guild and will not agree to the standard terms of a collective bargaining agreement with us,” Peterson told the ITV executives, reminding them that “fighting the guild is counterproductive for a company that seeks to solidify and expand its presence in American television.”

A spokesperson for ITV Studios America said the company “is very excited about the series … but we are not yet in production and no airdates have been set.” NBC declined comment.

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Related: NYC Councilman: ITV Studios Unfair To Labor

NBC said the show will feature comedy sketches, musical numbers, mini-game shows, hidden-camera pranks on celebrities and appearances by A-list stars. Harris said in a statement that he has watched the UK version and “couldn’t stop smiling. Now that I’ve seen many seasons, my face hurts. It’s a game-changer. Nothing like this has been done before, and its unique structure fits right into my random skill set. I can’t wait to roll up my sleeves and have some fun!”

But crossing a picket line, if it comes to that, isn’t that much fun — especially for a union supporter like Harris, who hosted the 2009 WGA West’s awards show.

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“ITV is not going to be able to get any guild writers unless they sign a contact,” Peterson told Deadline. “It’s a simple proposition that I guess they don’t understand over there in England.”