The labor dispute over NBC’s “The Biggest Loser” remains unresolved after four days of protests and a production crew strike because producers are using non-union crew to shoot the reality show.

The California Labor Federation declared a strike sanction Thursday on behalf of the Intl. Alliance of Theatrical Stage Employees against the series and its production entities, Reveille Prods., 25/7 Prods. and 3 Ball Prods.

“A television show is only as good as its production crew,” said Art Pulaski, executive secretary-treasurer of the federation. “The striking crew members on ‘The Biggest Loser’ put their heart and soul into creating a quality show each and every week. It’s shameful that the show and its production entities have shown so little respect for those who are so integral to the show’s success.”

The L.A. County Federation of Labor held a news conference Tuesday to announce that it had officially endorsed the strike. About 50 pickets protested Thursday outside the set near Calabasas.

IATSE announced the work stoppage a week ago as more than 50 crew members had voted to strike over producers’ refusal to sign an IATSE deal. NBC and the production entities have not commented.