Mayor Cherelle Parker’s return-to-office policy caused a rift with union leaders. Here’s what could happen next.

The backlash was immediate.

Before Mayor Cherelle L. Parker even announced publicly on Monday that she’ll require all city employees to return to in-person work full-time by this summer, leaders of the union that represents much of the city’s professional staff revolted. They said that their members are incensed and that the administration did not negotiate the change with them.

Parker said the policy is not subject to collective bargaining, and she acted unilaterally to end hybrid work for thousands of government employees.

The announcement caused a major rift between the Democratic mayor and AFSCME District Council 47, one of the city’s largest unions, less than six months into Parker’s first term. And it comes just weeks before the union’s contract with the city is set to expire, setting up an increasingly contentious negotiation.

During an interview with the Inquirer’s editorial board Tuesday, Parker said her administration continues to work with the city’s municipal unions and that she expected some employees to “have some challenges and concerns about” the change.

“I know we’re not always going to agree,” she said. “But I’ve been elected by the people to do the best I can with making the best decision possible to help move our city forward, and that’s what I’m trying to do. I think this is in the best interest of the city.”

The problem — for both sides — is that there is no consensus among employers and public-sector unions as to whether a return to the pre-pandemic status quo has to be negotiated.

Here’s what each side is saying and what could happen next.

During a news conference Monday, Parker said she does not believe her policy needed to be bargained with the unions but did not offer a further justification. She said she expects ongoing “hearty and healthy discussions” with the municipal workforce about the policy, and she emphasized that her administration announced an expansion of perks like parental leave and sick-time flexibility.

» READ MORE: Mayor Parker wants employees in-office to help Center City bounce back

Parker added that the workforce was “at the center” of her decision-making.

“We can’t run the city and make good on any of [our] promises without the men and women who do it on a daily basis,” she said. “I respect them, I appreciate them, and I value them.”

Two organized labor leaders who represent building trades and service workers said in statements they support the mayor’s decision.

“The Building Trades stand with Mayor Parker,” said Ryan Boyer, a close Parker ally and the head of the Philadelphia Building and Construction Trades Council. “It’s important to the vitality of the city and equity with those workers that don’t have the option of working remotely.”

The city and the union discussed the return-to-office policy once and had another negotiating session scheduled for this week, according to David Wilson, president of AFSCME Local 2187 of District Council 47, which represents much of the city’s professional and administrative staff. He said the mayor implementing the policy unilaterally amounts to the city walking away from bargaining.

District Council 47′s contract with the city does not include a specific provision as to whether an end to hybrid work flexibility must be negotiated. But union officials and city leaders did negotiate telework conditions with individual departments during the pandemic under former Mayor Jim Kenney.

Gennifer Reed, president of Local 2186, which represents city supervisors, said the contract also has for more than 30 years included options for “alternative” work schedules and “flex time.” Those provisions say employees can adjust their working hours and deviate from a typical 9-to-5, five-days-a-week schedule with the agreement of their department head.

Parker’s policy doesn’t change workers’ hours — just their working location.

Francis Ryan, a professor of labor at Rutgers University who wrote a book about AFSCME in Philadelphia, said hybrid work arrangements are a “historically unique example of discussing workplace hours.”

“But I think it fits in with the context of what collective bargaining normally does,” he said. “When you look at the history of collective bargaining in the public sector, there are cases where flex time and other kinds of work arrangements have been bargained.”

Experts and labor lawyers say there is not a consensus between employers and unions as to whether return-to-office policies need to be negotiated, and requirements for negotiation can vary widely, based on individual unions’ contracts.

Joseph E. Slater, a professor at the University of Toledo College of Law and an expert in public-sector labor law, said there are three ways to classify whether a topic is subject to collective bargaining:

Slater said he believes the first two options are “significantly more likely” than the third.

» READ MORE: City workers say they feel like ‘pawns’ for Center City revival as Mayor Parker pushes in-office requirement

Other jurisdictions have taken a variety of approaches. For example, the Pennsylvania state government developed telework agreements with four unions that represent public-sector workers.

At the federal level, agencies have negotiated hybrid conditions to varying degrees, but it is considered a mandatory subject of bargaining. Last month, the Department of Education announced that all staff would be required to work in-person at least five days per pay period, but the union that represents department employees said it had not agreed to the policy. Last week, the department postponed its plans.

The unions could fight the policy by filing an unfair-labor-practice charge with the Pennsylvania Labor Relations Board.

Slater said the board would then determine which, if any, parts of the policy the employer would have to bargain before implementing. Typically, an administrative law judge makes an initial ruling, which can be appealed to court.

Labor leaders have not yet said if or when they intend to take further action. In a statement, District Council 47 said only: “More to come.”