Ethical veganism is a "philosophical belief" and thus protected under the law, a tribunal has ruled for the first time worldwide in Norwich on Friday.
The landmark case was brought by vegan Jordi Casamitjana, who claims he was sacked by the League Against Cruel Sports because of his ethical veganism.
His former employer says he was dismissed for gross misconduct after disclosing the organisation invested pension funds in firms involved in animal testing. After raising the issue to no avail, Casamitjana then informed his colleagues and was sacked.
The judge said that ethical vegans should be protected in British workplaces under the same protections outlined in the Equality Act 2010 that shield religious beliefs.
In an interview outside court, Casamitjana said he was "very happy" with the ruling.
"It's so good for me and for all the vegans in the world to know that any country has started to recognise legally the importance of veganism as a protected belief," he added.
The decision of whether Casamitjana was in fact dismissed due to his ethical veganism will be decided in another ruling due in late February.