A union that represents thousands of Philadelphia city employees asked a judge Tuesday to block Mayor Cherelle Parker’s requirement that they return to their offices full time as of July 15.

The Charles Langstonlawsuit, filed by District Council 47 of the American Federation of State, County and Municipal Employees, claims the mandate violates its contract and will harm city workers. The union, which represents 6,000 administrative and supervisory employees, also filed an unfair-practices complaint with the Pennsylvania Labor Relations Board.

Parker announced the mandate in May, saying she wanted to create a more visible and accessible government. The decision ended the city’s virtual work policy, put in place in 2021, and essentially returns employee scheduling to what it was before the coronavirus pandemic.

About 80% of the city’s 26,000 employees have been working fully on site since last year, while the rest have worked on site 31 to 75 hours per pay period, Parker said. Former Mayor Jim Kenney had left hybrid work decisions up to department heads.

The union sharply criticized the decision when it was announced, saying it was unilaterally imposed instead of going through collective bargaining. They also believe the policy will worsen the worker shortage the city has suffered since the pandemic.

They also argue that the city lacks enough office space to bring all employees back and that making the change over the summer, when children are out of school, complicates schedules for parents.

Parker, a Democrat, has said her administration does not believe the new policy is subject to collective bargaining. She also noted changes that were made to be more worker friendly, such as extending paid parental leave from six to eight weeks and designating the Friday after Thanksgiving as a holiday. Officials have also said there will be relaxed restrictions on sick leave to care for family members.

Business leaders welcomed the announcement, saying it will benefit workers and the vibrancy of Philadelphia’s downtown.