Sinn Féin TD Brian Stanley said he is “truly sorry” for the hurt and anger he caused by posting two controversial tweets.
The Public Accounts Committee (PAC) chairman posted a tweet last month in which he appeared to glorify historical killings of British soldiers by the IRA.
He has also been criticised for a 2017 tweet he sent that appeared to comment on the sexuality of Fine Gael leader Leo Varadkar.
In a statement to the Dáil, Mr Stanley said: “As we now advance reconciliation in our country we need to be able to talk about the past in a way that doesn’t cause deep division.
“We must be sensitive in how we talk about the past, and respectful that the views that others hold about the past may be different.
“I accept that my tweet regarding the ambushes at Kilmicheal and in Narrow Water was insensitive and it caused hurt and anger.
“Words can do that and my words did that, and for that I am truly sorry.”
Homophobia
Mr Stanley admitted the tweet he sent regarding Mr Varadkar's sexuality was open to interpretation and apologised.
“Homophobia is abhorrent to me, and I absolutely deplore prejudice of any kind, and always have. I realised that many people who have read my tweets, they don’t know me personally," he said.
“They don’t know my record, they don’t know my stance on issues. But my record is not a defence, nor does it take away from any hurt caused.”
Mr Stanley said he had tried to contact the Tánaiste today to apologise for the post.