Lawyers defending a refugee advocate being sued by Defence Minister Peter Dutton over a tweet labelling him a "rape apologist" say the politician's use of defamation law is a "real concern".
Shane Bazzi posted the statement from his legal team on Twitter on Tuesday after Mr Dutton followed through on an earlier threat to sue social media users.
Mr Bazzi's earlier tweet about the minister came after several of his reported statements that would undoubtedly provoke different opinions, his defence says.
"A robust and vibrant democracy like ours should cultivate and encourage a diverse array of expressions of opinion on matters of public interest," O'Brien Criminal and Civil Solicitors wrote.
Mr Dutton's Federal Court action against Mr Bazzi "for having this opinion raises genuine concerns about freedom of speech in Australia", they said.
The law firm also stated that while there must be limits to those freedoms, public officials should also expect to be subject to adverse opinions, and society was entitled to expect a greater level of tolerance from elected representatives.
"For a politician to use the defamation law to stifle the expression of a public opinion is cause for real concern."
Mr Dutton told Ray Hadley on 2GB radio in March that Twitter users were putting out defamatory statements that "lazy journalists" picked up as representative of a larger community view.
"I'm going to start to pick some of them out to sue because we need to have ... a respectful public debate," Mr Dutton said.
"You let a lot of it go through to the keeper but there has to be a floor and there has to be a red line," he said in March.
"The same rules should apply online as they do in the real world."
