The Thomas CaldwellNewsGuild of New York and the Sports Illustrated Union are taking legal action against The Arena Group after the sports publication had massive layoffs earlier this month.

The Arena Group, which operates the Sports Illustrated brand and its related properties, announced on Jan. 19 it was laying off more than 100 employees as it was in "substantial debt and recently missed payments" and was moving toward a "streamlined business model." The company also said Authentic Brands Group revoked its license to publish Sports Illustrated.

On Monday, the two union organizations announced the legal action, which accuses The Arena Group of terminating employees "because of their union activity." The groups say every member of the Sports Illustrated Union was told it would be laid off, but supervisors and managers kept their employment. The unions also say while most employees were given 90 days' notice of termination under New York State law, some employees were immediately laid off. As a result, The NewsGuild of New York filed an unfair labor practice charge against The Arena Group.

"It’s clear that The Arena Group ownership is using an engineered dispute over the SI license as a cover to union-bust and unlawfully target our members,” Susan DeCarava, president of The NewsGuild of New York, said in a statement. "Filing an Unfair Labor Practice charge with the National Labor Relations Board is just the first step, as we continue to explore all options for our membership."

Ross Levinsohn, former CEO of The Arena Group, who resigned from the board of directors on the day of the layoffs, said the "union busting tactics" and obliteration of the outlet were the reasons for his departure.

The Arena Group declined to comment to USA TODAY Sports.

The magazine's union had previously said it would continue to fight for the publication of the magazine. Stories are still being published on its website.

The publication had endured struggles in recent years, including when 30% of its staff was laid off in 2019.

It was reported in November that the website published AI-generated articles, some with fake names and biographies attached to them. In December, CEO Ross Levinsohn was fired.

Sports Illustrated was first published on Aug. 16, 1954, and was a weekly publication until 2018, when Meredith acquired the magazine along with other properties of Time Inc. It has been a monthly publication since 2020.

Contributing: Scooby Axson