A DUP councillor being sued by Sinn Féin MP John Finucane over unfounded Twitter claims of supporting the IRA is set to argue his comments were justified, the High Court has heard.
Marc Collins has raised the defence that any members of the republican political party must also allegedly back the paramilitary organisation, a judge was told.
But a lawyer for Mr Finucane contended those grounds were "unsustainable and absurd".
It also emerged that the libel action may now be decided by a trial by jury.
Defamation proceedings relate to a tweet published in November 2019 during the Westminster election campaign.
Mr Finucane was standing as Sinn Fein’s candidate for North Belfast - a seat he went on to win.
At the time there was media coverage of banners which attacked and made allegations about him and members of his family.
A previous court heard that a posting on Mr Collins’ Twitter account included the baseless claim: “He supports and promotes the IRA, he isn’t innocent by any means.”
There is no suggestion of any truth in the contents of the tweet.
In June last year the DUP politician was suspended from Mid and East Antrim Borough Council for eight months after a watchdog standards investigation found he had breached the code of conduct.
He is now facing a lawsuit seeking damages over the contents of the tweet.
In a statement of claim Mr Finucane contended it had a defamatory meaning that he not only supports and promotes the IRA, but also condoned acts of terrorism perpetrated by the organisation.
However, Mr Collins is defending the action on the grounds of justification and honest comment.
At a review hearing today counsel for Mr Finucane set out the argument raised by the DUP councillor.
Peter Girvan said: “The defendant wants to make the case that anyone who is a member of Sinn Fein supports the IRA by virtue of being a member of Sinn Fein.
“(Our) argument is that’s completely unsustainable and absurd.”
The court heard there is no decision yet on whether the action should be determined by a jury or a judge sitting alone.
Barrister Paul Bacon, representing Mr Collins, indicated that some outstanding issues may be narrowed before the case is listed for trial.
“We are at an impasse currently,” he added.
Mr Justice Rooney agreed to review the case again later this month.