Former federal Labor leader Mark Latham has been ordered to pay a fellow NSW MP the maximum available penalty for vilifying him for his sexuality.

The 65-year-old will have to pay Alex Greenwich $100,000 after a tweet directed at him was found to be unlawful sexual harassment.

The sexually explicit tweet from Latham – now an independent member of the NSW upper house – had previously been ruled defamatory by the Federal Court.

It came in response to a post quoting Greenwich describing Latham as a “disgusting human being”.

The online sparring match between the two politicians followed violent protests outside a church in Sydney’s south-west, where Latham was giving a pre-election speech in March 2023.

About 250 mostly male counter-protesters violently attacked police and 15 LGBTQI protesters.

The NSW Civil and Administrative Tribunal imposed the maximum penalty due to the extreme abuse Greenwich received and the intense impacts he felt.

It found Greenwich had suffered extreme psychological damage as a result of Latham’s actions.

The tribunal did not order Latham to apologise, saying it would be pointless given it would likely not be genuine.

Greenwich welcomed the decision and said the result was a landmark ruling for LGBTQIA+ rights in NSW.

“This decision sends a clear message: Public figures are not above the law, and online platforms are not a space for unlawful vilification,” the independent member for Sydney said.

“The tribunal has made clear that the law does not require anyone to endure unlawful vilification or sexual harassment.”

Latham was ordered to remove any material from his social media that vilified Greenwich on the basis of his homosexuality and to refrain from making any more unlawfully vilifying statements.

He was also ordered to pay Greenwich’s legal costs.

-AAP