Elon Musk is in tweeting purgatory again.
A federal appeals court ruled Friday that the billionaire must delete his 2018 Twitter post suggesting that Tesla Inc. workers could lose stock options if they formed a union and joined the UAW, as it violated labor law.
The decision is a victory for the National Labor Relations Board and a blow to Tesla, which has vehemently opposed the UAW's years-long effort to unionize the EV maker's workers.
It also puts Musk in the awkward spot of having to retract one of his many incendiary tweets after he's become the owner of Twitter Inc.
The tweet said: "Nothing stopping Tesla team at our car plant from voting union. Could do so tmrw if they wanted. But why pay union dues and give up stock options for nothing?"
The labor board had ruled that Tesla repeatedly broke U.S. law, including by firing a union activist, and directed the company to ensure that its chief executive officer's threatening tweet is erased from his feed. Tesla has argued that Musk's tweet was protected by the First Amendment guarantee of free speech.