Tesla Inc (NASDAQ:TSLA) cannot restrict its workers' ability to display union insignia at work, such as wearing union t-shirts and buttons, says a ruling by the National Labour Relations Board (NLRB).
In their majority opinion, the board said it's "unlawful for Tesla to maintain a policy requiring employees to wear a plain black t-shirt or one imprinted with the employer's logo, thus prohibiting employees from substituting a shirt bearing union insignia."
Employees at Tesla were reportedly told they could not wear shirts bearing the United Auto Workers logo when the policy went into effect in 2017.
In its testimony to the board, Tesla argued that its black shirts prevent damage to cars and allows the firm to maintain "visual management" of its employees - a claim that was rejected by NLRB.
"With today’s decision, the board reaffirms that any attempt to restrict the wearing of union clothing or insignia is presumptively unlawful," said NLRB chairman Lauren McFerran in a media statement.
There are still special circumstances that allow employers to restrict union insignia size and placement.
A prominent example of a "special circumstance" classification is Wal-Mart's argument that customer-facing employees should dress professionally.
Incidentally, a dress code at Tesla did not impede labour organising, for it was ruled by a judge in 2019 that the company had been sabotaging unionisation efforts.
Musk was also forced to delete anti-union tweets from 2018.
Musk also has criticised a bill from Democratic House lawmakers in September 2021 that would benefit unionised electric vehicle manufacturers and blamed the bill on "Ford/UAW lobbyists."
Musk invited the United Auto Workers union this year to hold a union vote at a Tesla factory, though this was less a call for protecting labour rights at Tesla than a dare to prove unionisation isn't necessary.
Although no vote has taken place, the NLRB's recent ruling should make it easier for organisers to demonstrate solidarity.