Finance Minister Paschal Donohoe has piled fresh pressure on Fianna Fáil leader Micheal Martin after saying any Dáil vote sanctions against TDs Timmy Dooley and Niall Collins are up to the opposition leader.
Mr Donohoe made the comment as he separately claimed he has to take Mr Dooley and Mr Collins widely criticised explanation of what happened "at face value" unless more information emerges.
An independent Oireachtas investigation into the controversy published on Thursday morning failed to sanction either Mr Dooley or Mr Collins over the case.
This is because officials do not want to impact on an ongoing Oireachtas ethics committee investigation into the same case.
Speaking to the Irish Examiner at a tax conference event in Dublin on Thursday afternoon, Mr Donohoe said he is deeply concerned about what happened involving Dáil votes.
Asked if any further sanctions should take place, he targeted Fianna Fáil leader Micheal Martin by saying any such decision is a matter for the ethics committee and the opposition leader.
"In terms of sanctions that is a matter for the relevant Oireachtas committee, and the Oireachtas committee is now evaluating whether further action needs to be taken against those TDs.
"Any sanctions the leader of Fianna Fáil chooses to make is a matter for them."
Asked if he believes Mr Dooley and Mr Collins explanations, Mr Donohoe said he has no other choice at this stage, saying:
"I have to take the statements that both deputies have made in the Dáil this afternoon in good faith, and in good value, but I want to strongly endorse what the ceann comhairle has said."
He added that what happened in Dáil votes is a serious concern and has "very regrettably eroded" public confidence in Irish democracy.
"I take the work that we do in the Oireachtas deeply seriously. I believe politics is a hugely important role.
"And anything at all that diminishes the standard of that in the eyes of our citizens I think is a real disappointment, particularly about something that is so fundamental about being a representative and a citizen, which is casting a vote."