Union members rallied outside the Ridge Hill complex in Yonkers Thursday urging workers not to go inside.Members of Iron Workers Local 40 staged the protest because they say non-union labor is being used to build part of the structure. Union leaders say developer Forest City Ratner signed a project labor agreement guaranteeing all work would be performed by unions. The controversial $600 million project includes national retailers, restaurants and a multiplex movie theater in addition to a hotel office space and condos. Union officials say Forest City Ratner sold a parcel of the land to a non-union developer to build the condos. The iron workers have been protesting since construction on the condo project began. On Thursday, members from other unions joined in because they say eventually this project will affect their trades too.