A Catholic priest has ramped up his campaign to close a legal loophole that allows the use of the "gay panic" defence.

Under Queensland law, an alleged non-violent homosexual advance can be used as a partial defence for murder or assault.

Father Paul Kelly has been fighting to close the loophole since a man was bashed to death on the grounds of his Maryborough church in 2008.

A recent State Government decision to scrap a planned tightening of the loophole has breathed new life into Father Kelly's campaign.

His online petition for change has now garnered more than 189,000 signatures, and attracted support from English comedian Stephen Fry and American actress Sophia Bush.

"Within a couple of days it's jumped tens of thousands of signatures. It's extraordinary," he told ABC News Online.

"What it says is that a broad sector of the local and world community sees that a law that even unintentionally has a negative effect on one particular group is not allowed.

"And whatever their beliefs, whatever their religion, they won't let that get in the way of protecting peoples' basic rights to safety."

Father Kelly says the law encourages a culture of hate.

"What it's doing, without acknowledging it, is saying 'our society can understand that someone can lose it and lash out violently because they have such a revulsion to certain things that are deep in their prejudice, misunderstanding and fear'," he said.

Under the state's provocation law, defendants can argue they found a homosexual or heterosexual advance so offensive and frightening that they lost control and violently lashed out.

Father Kelly had a close encounter with the use of the defence four years ago, when Wayne Ruks was killed on the grounds of his church by two men.

Father Kelly says the men claimed in court that Mr Ruks had made an unwanted sexual advance.

"His mother, during the trial, said it was a load of rubbish. She said her son was not gay, that he had a 10-year relationship," he said.

"She viewed footage of the CCTV video of the incident, and so did I, and the victim came nowhere near the attackers, and did not touch him."

Father Kelly says the court rejected the provocation claim and the offenders were sentenced to manslaughter.

But he believes the defence still influenced the outcome of the trial.

"The jury was aware of that explanation, the judge took it in the mix of the considerations of that trial," he said.

"People say the case didn't turn on that in the end, but that's just word play. If it didn't turn on that why allow it to be brought up at all?"

'Tough on crime'

The provocation defence has been altered since then. In 2011 it was changed so it could not be used based on words alone, other than in extreme circumstances.

The previous state Labor government had planned to further tighten the law - a change Attorney-General and Minister for Justice Jarrod Bleijie has scrapped.

Mr Bleijie says the idea of gay panic is a political tool concocted by the Bligh government.

"It is important to understand that the defence of provocation is not based on one’s sexuality. It is open to any Queenslander," he said in a statement to ABC News Online.

"In 2011 ... the laws were strengthened making provocation as a whole harder to establish as a defence.

"To date, these strengthened provocation laws have not been used in a murder trial and only took effect in April 2011.

"The LNP remains tough on crime, however given these laws are yet to be tested, does not intend to make any further amendments to the provocation defence at this time."

'Concocting stories'

But Father Kelly says Mr Bleijie is missing the point.

"I have a feeling the Government thinks 'this is just a gay agenda, this is a concocted thing to get the gay rights thing going'," he said.

"And that annoys me, because it's not what I'm on about, it's not what raised my concerns, and if anyone's concocting anything, it's violent men who are concocting stories, or imagining stories or even reacting to the smallest of things and being excessive in their violence.

"It's also been used against racial minorities, and against women in abusive relationships. The man claims the woman provoked him and that's why he bashed her so badly she died.

"That's intolerable. I don't think there's any place for a defence against killing someone other than, honestly, a fear for one's life."

The provocation defence has been abolished in Victoria, Western Australia and Tasmania, and a NSW parliamentary committee is currently conducting an inquiry into the defence in the state.

And despite almost having 200,000 signatures on his petition, Father Kelly is not holding his breath for action in Queensland.

"I fear that if it was 2 billion, it wouldn't change this present Government," he said.

"I hope I'm wrong."