Bosses want their employees back at their desks—making the most of the massive investments companies have made in commercial real estate, while employees want to hold onto their newfound freedom.

As global companies ramp up efforts to bring their staff back to the office, experts have warned there is a growing wave of resentment that could prove a thorn in the side of company cultures for years to come.

But not only that, return-to-office mandates could also present a hiring problem if employees do decide to leave en masse, as many job seekers are now prioritizing a more flexible working schedule.

Resentment impacts productivity

For Nick South, a managing director at BCG based in London, the “smart” bosses aren’t those who overly committed to remote work (take Meta CEO Mark Zuckerberg, for example, who said 50% of the company would be remote by the end of the decade, before issuing an RTO mandate this year) or doubled down on in-person rules either.

The managers who navigated this path successfully are those who promised to experiment with new models, grasping that businesses don’t need to focus on where t,heir staff work, but how they work.

“There’s an intrinsic thing that when staff feel entrusted and empowered and have agency over their work, you get extra effort from them,” South told Fortune in an interview. “When [employees] are told to do something but they’re not convinced by the rationale people get resentful, which impacts productivity.

“If organizations are smart, they recognize employees want flexibility and will try and make that work.”

Managers also need to approach the issue from the perspectives of their teams, South explained. Where managers will often spend hours a day coaching, training, and mentoring, it can be easy for them to assume everyone else needs their level of in-person interaction.

Yet for some staff, who may be cracking on with reports or data analysis, there may be far more value in working somewhere remotely to get the job done quicker.

“The shoes you’re in shape the perception of how much of your time needs to be interacting with others,” South said.

South’s warning reflects data compiled by BCG, which found that the less involved individuals were with their return-to-office agreements, the more likely they were to be unhappy and as a result, leave.

Of the 1,500 employees BCG surveyed those who were dissatisfied with the work seups were 2.5 times more likely to leave than those who were happy with their arrangements.

In fact, the idea that mandates equal productivity is a myth, South said, pointing out that before the pandemic, when staff tended to be in five days a week, plenty of people coasted through their careers or “quiet quit.”

As a result, mandates could be swapped out for “mixed models,” South suggests, in order not only to protect productivity but also increase diversity—BCG found flexibility was “critical” to maintaining a diverse workforce, with 90% of surveyed women, caregivers, LGBTQ+ people, and people with disabilities categorizing flexible work options as important or very important in staying in or leaving their job.

Keep it consistent

Every expert Fortune spoke to about the return-to-work battle agreed that at least some time in the office is necessary to build a positive work culture—whether it’s to help train younger staff, enable employees to feel more involved, or simply because most people enjoy interaction with others on some level.

The data is also beginning to uncover the longer-term reality of remote work. In July 2023 a study from the National Bureau of Economic Research found the productivity of those randomly assigned to working from home was 18% lower than those in the office.

Moreover, people who actually prefer to work from home may have an unpopular reason—they’re 27% less productive when working remotely than people who prefer being in the office, who are 13% less productive at home.

“The key thing is being consistent in the communications so that employees know where they stand,” PwC’s senior partner, Kevin Ellis, told Fortune.

“In 2020 we polled our employees and asked what they wanted. Unsurprisingly it was on the fence, but the average was two to three days a week, and we’ve stuck with that. We’ve always thought it was important to be consistent.”

Ellis added that just because some employees are choosing to come in four or five days a week, he wouldn’t alter the expectation: “I don’t want to change the rules now, that doesn’t feel right, because you’ll get the resentment and people feel detached.”

In its London office PwC has done everything it can to ensure staff don’t feel their time is “wasted” in the office: be it by designing more collaboration space, offering discount food, or organizing plenty of social events.

“Hybrid is here to stay, but you’ve got to be consistent with how you apply it and talk about it. You can’t tell someone they’re not getting promoted for not coming in the office if they don’t know what the rules are,” Ellis said. “It’s about being level with employees about what the rules are, and advertising the benefits of coming into the office.”

You might struggle to hire

Companies that lose staff over strict return-to-office mandates might struggle to replace them.

While the likes of Goldman Sachs and JPMorgan are insistent on getting their people back to the office, a study released this summer found that half the employees in finance would quit if their bosses asked them to go to the office more often.

And a raft of other industries have got the same idea: Disney, Google, Meta, and even remote-work enabler Zoom want their people back at their desks.

Yet a study of 32,000 employees released last year found that 64% of workers across a gamut of sectors would quit if their company rolled back on flexible working policies.

The exodus isn’t balanced by an influx of people who want to be in the office. Last year McKinsey and Company asked 25,000 Americans what their top three priorities were when it came to a new job. First was better pay, then better career opportunities, then came the need for flexible work arrangements.

The report, titled the American Opportunity Survey, adds: “Competition for top performers and digital innovators demands that employers understand how much flexibility their talent pool is accustomed to and expects.

“Employers are wise to invest in technology, adapt policies, and train employees to create workplaces that integrate people working remotely and on-site (without overcompensating by requiring that workers spend too much time in video meetings).”

Autonomy is king

Resignations over return to office mandates are part of a wider landscape of resentment, warned recruitment boss Andrew Crapuchettes.

The CEO of Idaho-based recruitment firm Red Balloon told Fortune people may not quit solely because of the office, but because they feel they’re viewed as a “cog” for the company as opposed to having autonomy.

The remote-work battle is just “part of the story,” which Crapuchettes feels is actually more about workers’ demands for freedom: “During COVID many people’s relationship with work fundamentally changed. They enjoyed the work-life balance, being treated like a human being, and they would like to keep that.”

The CEO told Fortune the “tug-of-war” over hybrid versus office is “not going away anytime soon,” but added the power is still in the hands of the job seeker.

Indeed, jobs posted on Red Balloon offering a remote option get three times the number of applicants as their in-office competition.

“Employees are still winning this debate,” Crapuchettes—himself an advocate of getting his staff into the office on a flexible basis—said.

“Any employer who wants to have everyone come back to the office needs to be a little bit more willing to pitch the idea and build an employment brand, rather than mandate it with a top-down, heavy-handed approach.”