The Teatro Real is looking for 100 volunteers to be supers in its upcoming production of “Idomeneo.”

According to Platea Magazine, the theater is following in the footsteps of the Palau de Les Arts de Valencia, which contracted volunteers for its “Magic Flute” production instead of paid performers. The controversial decision will require the volunteers to attend 18 rehearsals and be present during the nine performances of the Robert Carsen production. It will also require more than 100 hours of free work.

The announcement has caused controversy with unions denouncing the move and leaders forming a petition against the general managers of the Teatro Real.

“Idomeneo” is set to open Feb. 19 and will star Eric Cutler and Jeremy Ovenden sharing the title role. The production will also star David Portillo, Eleonora Buratto, Sabina Puértolas, and Alexander Tsymbalyuk.