A Californian judge has ruled that Tesla violated labor laws in 2017 and that a tweet sent by Elon Musk in 2018 broke the law by interfering with legitimate union organizing.

Reuters reports that this Friday, a California administrative law judge ruled that Tesla must "read a notice to workers explaining their rights in a meeting requiring attendance from Chief Executive Elon Musk." The ruling came after the court found that on a number of occasions in 2017 and 2018 Tesla violated the National Labor Relations Act.

One of the key violations cited was a tweet shared by Musk in response to criticism of Tesla's workplace safety standards. The judge ruled that the tweet amounted to “threatening employees” with loss of stock options if they vote in favor of the union.

While the ruling calls for the reinstatement and an offer of back pay to a pro-union employee and revocation of a warning issued to another employee, Tesla can still appeal the ruling.

In other news, Elon Musk has announced plans to launch his SpaceX Starship into space in the coming six months.