Solidarity TD Paul Murphy is set to lodge a formal complaint claiming that Taoiseach Leo Varadkar and ministers Charlie Flanagan and Mary Mitchell O'Connor defamed him during a heated Dáil exchange.
Independent.ie reports that in a letter to be sent to the Ceann Comhairle today, Mr Murphy will claim Mr Varadkar's accusation that events at the Jobstown protest amounted to "thuggery" broke Oireachtas rules.
Mr Murphy alleges the Taoiseach description of the demonstration suggests he was involved in 'anger', 'swear words' and throwing a water balloon.
"These are false allegations, which are defamatory," he writes.
He goes on to cite Justice Minister Charlie Flanagan's interruptions during the debate as "implying deputy had previously made threats against members of the House".
In reference to comments made by Minister of State Mary Mitchell O'Connor, he says she defamed him "when she stated 'two women were kept in a car', implying that this act amounted to false imprisonment when a jury has found this not to be the case".
The letter, which is to be lodged today, is signed by Mr Murphy and his colleagues Ruth Coppinger and Mick Barry.
The complaint comes as the Ceann Comhairle Seán Ó Fearghaíl told the Irish Independent sanctions for abusing Dáil privilege needed to be beefed up. Mr Ó Fearghaíl said a point had been reached "where we do need to take action".
"One cannot escape the reality that privilege is a frequent issue now arising for us," he said.
"If you look at the sanction currently in place the member is sanctioned by their peers. I think in the old days it would have been considered a sufficient reprimand that someone was sanctioned by their colleagues.
"Now some members might consider it a badge of honour to be sanctioned by their colleagues."
Mr Murphy used privilege this week to claim "numerous gardaí lied under oath in a coordinated way" during his trial for false imprisonment. However, it is likely to be September before the Oireachtas Committee on Procedure decides whether his comments breached the rules of privilege.
Meanwhile, there was uproar in the Dáil again yesterday when People Before Profit TD Gino Kenny described the parliament as "a kip".
The Dublin Mid-West deputy's comment will now also have to be considered by the Committee in September with the Ceann Comhairle indicating to the Irish Independent that he believes Mr Kenny crossed the line.
He was arguing a bill seeking to legalise medicinal cannabis should not have been shelved and accused the Government of leaving people with chronic pain "completely ignored".