A controversial politician’s “abusive obsession” with a fellow MP has exposed him to ongoing hatred and ridicule, a tribunal has been told.

NSW independent MP Alex Greenwich continued his legal fight against controversial former federal Labor leader Mark Latham today, having sued him for homosexual vilification and workplace harassment.

The case relates to a sexually explicit tweet the Federal Court has previously ruled as defamatory and subsequent media appearances made by Latham, who sits as an independent in the state parliament.

In a passionate address, Greenwich said the tweet had sought to define him as a “disgusting sexual act” and a threat to children.

“(He has) an abusive obsession with me, it began with that tweet and it has not stopped,” he told the NSW Civil and Administrative Tribunal today.

“I have never been so diminished, demeaned, dehumanised by someone … this was the first time in my political career I’d been so fundamentally attacked for who I am and my sexuality.”

Greenwich added his electorate office had been “inundated” with abuse after Latham’s tweet and subsequent interviews.

“I have as an openly gay MP … of course at times received homophobic abuse (but) I have never been defined by someone as a disgusting sex act,” he said.

Latham repeatedly interjected from the public gallery, drawing a sharp warning from senior tribunal member Mandy Tibbey.

Greenwich, who is a vocal advocate for the LGBTQI community, received $140,000 in damages in a Federal Court suit against Latham in 2024.

He sued the former NSW One Nation leader in the Federal Court over the tweet, which was sent days after the state election and described a sex act in explicit terms.

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

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

About 250 mostly male counter-protesters violently attacked police and 15 LGBTQI protesters who had set themselves up outside the Belfield church.

Greenwich’s lawyer Prue Bindon said recent tweets from the former Labor leader had subjected her client to “further hatred and ridicule … from members of the public”.

After his lawyer objected to the tweets being formally tendered as evidence, Latham loudly complained about “another whinge-athon from the European prince”, a reference to Greenwich’s links to Georgian nobility.

Latham has been embroiled in several scandals, including taking photos of women MPs without their knowledge, for which he has already apologised.

But a recent attempt to have Australia’s oldest parliamentary chamber officially censure him failed after the coalition opposition, the Greens and minor party MPs voted to adjourn the motion until October.

The independent MP spent the hearing live-tweeting proceedings, including defending his postings as true.

“No court or tribunal should be used for restricting the legal, authentic freedom of speech of an elected member of parliament,” he wrote.