Ronald Rhoades and his coworkers formed a union last October, concerned about unsafe rigging, overcrowding, and other conditions at the Morton, Illinois, shop where they built tractor decks.

However, by early 2022, the group of about 20 people had been laid off.

Workers said the company, G&D Integrated, had closed the factory after losing a decade-old contract with a Japanese company. Another motive, according to the welders, was retaliation for the union effort.

The welders filed complaints with the National Labor Relations Board about the closure, part of a significant increase in worker grievances this year alleging retaliatory shutdowns and other illegal anti-union activity.

Overall, the numbers are still small, but organizers say store closings are one-way companies have tried to suppress union drives in the aftermath of the pandemic and rising economic pressure.

When asked why the shop had closed, Fisher responded via email, directing a reporter to the company’s statement.

The issue would have gone unnoticed if it hadn’t been for an increase in similar complaints following store closures at some of the country’s most prominent companies. Following union activity, Starbucks closed a number of locations this year. In Maine, executives closed a Chipotle location that was on track to become the first to vote on unionization.

The National Labor Relations Board (NLRB) sided with Starbucks workers in Ithaca, New York, this week, finding the company violated multiple labor laws during the closure of a store there. In a separate complaint, they agreed with the Chipotle workers, claiming that the company had illegally closed the store and laid off employees in order to discourage organizing. In both cases, officials requested that the stores reopen.

According to an NBC News analysis of NLRB data, workers have filed 34 unfair labor charges this year under the legal category for complaints about retaliatory shutdowns, relocations, and work subcontracting. According to NBC, that number has more than doubled since 2021, and has increased by about 80% since 2017-2019, the three years preceding the pandemic, when complaints ranged from 16 to 23 per year.

Many businesses claim that the closures are not directly related to union efforts, but rather reflect new economic constraints. For example, Trader Joe’s abruptly closed a wine shop in the heart of New York City where workers had been organizing.

Amy’s Kitchen, a vegetarian food manufacturer that closed a Bay Area factory in July after employees and a local union filed charges of unfair labor practices, said its costs had skyrocketed. According to Felicia Collins, the facility was losing more than $1 million per month due to a tight labor market, supply chain backlogs, and rising commodity prices, such as sunflower oil.

Closure violations, like many other aspects of labor law, can be difficult to prove and enforce. Employers are prohibited from explicitly retaliating against unionization, but they are permitted to close stores if the legitimate economic consequences of unionization require it. Furthermore, even when companies are found to have committed wrongdoing, there are no significant financial penalties: Companies must pay back wages for fired employees, minus any income earned in the interim. Companies may be required to reopen a closed location in exceptional circumstances.

Starbucks, the poster child for the current organizing surge, has been particularly aggressive in closing stores with union activity. Over the last year, more than 315 stores held union elections, with a large majority — 80 percent — voting in favor.

Starbucks announced the closure of at least 19 stores, mostly in urban areas, over the summer, citing safety concerns. According to data from Starbucks Workers United, the union that has been organizing the workers, more than 40% of the stores had union campaigns. Meanwhile, the stores that have filed for union elections, including the more than 250 where employees have voted to form unions, account for less than 4% of the companies’ approximately 9,000 corporate-owned stores.