Israel Folau is launching legal proceedings against Rugby Australia over the termination of his contract.
The fundamentalist Christian created a media storm in April for a post on his Instagram account that many viewed as homophobic.
It said drunks, homosexuals, adulterers and other groups "will end up in hell unless you repent".
His four-year contract - that local media report is worth over 3 million US dollars - was subsequently torn up.
Now, Folau is seeking a declaration from Australia's industrial relations tribunal, that his employment was terminated because of his religion.
In a statement, he said: "No Australian of any faith should be fired for practicing their religion".
And: "A nation made up of so many different faiths and cultural backgrounds will never be truly rich unless this freedom applies to all of us." He said his termination prevented him from playing a the peak of his career, and at the 2019 Rugby World Cup.
It's triggering a wider debate in Australia, about freedom of speech - and what control employers have over employees, outside of the workplace.
Rugby Australia was unable to provide immediate comment.