A union that represents emergency workers with the New York City Fire Department (FDNY) is speaking out against New York Mayor Bill de Blasio‘s (D) new rule that requires all city employees to either get vaccinated against COVID-19 or submit to weekly testing.

De Blasio on Monday announced that all city employees would be required to get vaccinated or begin undergoing weekly tests beginning by Sept. 13. This rule applies to the police department, school employees and all other agencies within the city government.

“FDNY EMS Local 2507 is strongly opposed to these new workplace mandates being forced upon all 4,300 of our members by Mayor de Blasio. These must be a subject of collective bargaining. The city and the mayor cannot simply disregard the civil liberties of the workforce,” the union said in a statement.