Arlene Foster has asked the speaker of the Dail to probe the conduct of a Sinn Fein TD whose inflammatory tweet celebrating the IRA has been branded "inappropriate and insensitive".
The First Minister has sent a letter to Ceann Comhairle Sean O Fearghail to consider what disciplinary action can be taken against Laois/Offaly TD Brian Stanley.
In a now-deleted tweet posted last Saturday, Mr Stanley praised two historical IRA attacks on the Army to his 3,700 followers.
"Kilmicheal (sic) (1920) and Narrow Water (1979) the 2 IRA operations that taught the elective of (the) British army and the establishment the cost of occupying Ireland. Pity for everyone they were such slow learners."
Mr Stanley, the chairman of the Dail's Public Accounts Committee, sent the tweet on the centenary of the Kilmichael ambush in 1920. He has since apologised.
The tweet received widespread condemnation.
In the letter, which has been seen by the Belfast Telegraph, Mrs Foster urges Mr O Fearghail to take action given the tweet has caused "enormous offence to both the victims of terrorism in Northern Ireland and wider society".
"I... have been contacted by many innocent victims of terrorism, from all backgrounds, who are deeply concerned by the philosophy which underpinned that tweet," said the DUP leader.
She said Mr Stanley's comments "fall well short of the behaviour expected of any democrat, let alone an elected TD", and urged the Dail chairperson to "consider whether such comments meet the standards required" of such a role.
Sinn Fein Deputy Minister Michelle O'Neill said yesterday Mr Stanley had deleted his "inappropriate and insensitive" tweet, adding: "We all have a responsibility to commemorate in a responsible manner."
The Taoiseach said he was "shocked and dismayed" by Mr Stanley's post. Micheal Martin said it had a "mocking tone" and was "deeply, deeply offensive".
Mr Martin said Sinn Féin needed to "deal with this in terms of Brian Stanley's position".