Ulster and Ireland rugby player Paddy Jackson has said he intends to sue Labour Senator Aodhán Ó Riordáin for defamation after the politician sent a tweet in the wake of the Belfast rape trial verdicts.

Mr Jackson was acquitted of rape and sexual assault at Belfast Crown Court on Wednesday in a unanimous verdict by the jury of eight men and three women. His teammate Stuart Olding was cleared of rape, Blane McIlroy was cleared of exposure and Rory Harrison was cleared of withholding information from police.

Aodhán Ó Riordáin tweeted a comment in the wake of the Belfast verdict and later deleted the message

In the wake of the verdict, Mr Ó Riordáin praised the complainant at the centre of the case and questioned the verdict. He later deleted the message.

A spokesman for the Labour party said on Thursday: “He knows it was wrong, he put his hands up and deleted it. He reacted before we got to him... he was reacting to the verdict when it came out.”

He added that social media guidelines have been given to all public representatives and party members who are active online.

A statement issued by KRW Law on behalf of Mr Jackson on Friday said: “On Wednesday, 28th March our client Patrick Jackson was unanimously acquitted by a jury at Belfast Crown Court on unsubstantiated charges.

“During the course of the trial our client and his co-accused regularly sought the protection of the court against the prejudicial excesses of social media.

“Despite Wednesday’s resounding declaration Patrick now finds himself resorting to the civil courts in order to seek protective action.

“Regrettably, KRW Law has had no option but to issue notice of intention to sue Senator Aodhán Ó Riordáin for defamatory comments made by him in the immediate aftermath of the jury’s verdict.”

Senior Associate Marie Hans of KRW said: “I can confirm we have issued pre-action libel correspondence against a named senator in the Republic of Ireland. The legal action relates to a tweet sent to a number of other persons before it was eventually taken down.”

She added: “We will not hesitate to repeat similar legal action against anyone, who deliberately or otherwise, sees fit to attack our client. We are examining carefully every item of social media commentary which seeks to challenge the integrity of the jury’s full endorsement of our client’s innocence. High court proceedings will issue shortly in both Belfast and Dublin”.