Mr Greenwich has sued the former NSW One Nation leader for defamation in the Federal Court over a tweet sent in March 2023, days after the state election.
Mr Latham's sexually explicit tweet was in response to an earlier post quoting the independent state MP describing him as a "disgusting human being".
Mr Greenwich claims Mr Latham's post defamed him by claiming he engaged in disgusting sexual acts and was not fit to be a politician.
Alex Greenwich said he'd tried to make the point that gay people are normal, like everybody else. (Bianca De Marchi/AAP PHOTOS)
He also alleges that statements made by Mr Latham and published in the Daily Telegraph in April 2023 defamed him further by accusing him of grooming children in schools.
Appearing in the witness box on Wednesday, Mr Greenwich said Mr Latham's defence angered and saddened him while making his stomach churn.
"I've been in public life for a long time," he told the court.
"I have ... tried to just make the point that gay people are normal, we're just like everybody else."
He denied Mr Latham's attempts to say he had gone into schools to talk with kids about sexual activity, he said.
"I don't and I wouldn't."
The online sparring match between the two politicians came after violent protests outside a church in Sydney's southwest where Mr Latham was giving a pre-election speech in March 2023.
Around 250 mostly male counter-protesters violently attacked police and 15 LGBTQI protesters who had set themselves up outside the Belfield church, the court heard.
In opening the case, Mr Greenwich's barrister Matt Collins KC said Mr Latham's tweet had unleashed a torrent of abuse, including death threats, despite only being online for two hours and 20 minutes.
"Our case is that in (that time), the course of Mr Greenwich's life changed," he told Justice David O'Callaghan.
Mr Greenwich gets panic attacks and feels anxious due to Mr Latham's attacks, the court was told. (Flavio Brancaleone, Dan Himbrechts/AAP PHOTOS)
The ex-One Nation leader had played on two tired stereotypes - that gay people were somehow depraved and a danger to children - when making his comments, Dr Collins said.
The barrister said while his client had attempted to engage in a bona-fide debate arising out of the violent incident, his opponent took a different route.
"Mr Latham, rather than engaging in that debate, went as low as possible," he said.
The abuse, both online and in messages to his Sydney electoral office, included claims Mr Greenwich was a groomer and a pedophile and that death was too good for him, the court was told.
The violent nature of these words caused serious harm to the independent MP, Dr Collins said.
"As a result of Mr Latham's conduct, he gets panic attacks, he feels anxious, he lacks in confidence," the barrister said.
"He finds himself becoming overly emotional, crying, he is reluctant to attend large gatherings out of fear."
Under cross-examination by Mr Latham's barrister Keiran Smark SC, Mr Greenwich denied his initial comment to a Sydney Morning Herald journalist calling Mr Latham a disgusting human being was intended to provoke.
"This was the first instance of political violence in an election period in Australia for some time," Mr Greenwich told the court.
"There had been a campaign by Mr Latham to target vulnerable members of the LGBT community.
"Those two things combined, I believe my assessment was appropriate."
The former federal Labor opposition leader will not take the stand.
The hearing continues.
8°C