One of New York City Opera’s key unions on Thursday charged the company with unfair labour practices and sought a court order blocking its proposed move out of Lincoln Center. The salvo from the American Guild of Musical Artists comes nearly a week after City Opera said it could no longer afford to stay at the arts complex.

Opera officials have so far remained silent on what they will present next season or where. The Guild, which represents singers, chorus members, dancers, stage managers and directors, said City Opera was using the move to break its contractual obligations and had refused to negotiate or provide any information about it.