Labour Senator Susan O'Keeffe has said she regrets enormously that she was not present for a selection committee meeting for the banking inquiry last Wednesday.
However, she said that she takes great offence at any questioning of her ability to do her job.
Senator O'Keeffe's absence from the meeting at Leinster House left the Government without a majority on the inquiry.
The committee had hoped to have its inaugural meeting tomorrow.
However, there have been objections to the selection of Fianna Fáil's Marc MacSharry alongside Independent Senator Sean Barrett.
The full Seanad has to approve the two names, but Government sources in the Upper House say they will block any motion that might be put forward seeking to endorse the selection of Senator MacSharry.
The row began when a number of Labour senators, including the party's proposed nominee Ms O'Keeffe, missed the selection committee meeting.
This allowed Fianna Fáil to back Mr MacSharry, whose inclusion puts the Government in a minority on the proposed inquiry.
Ms O'Keeffe said she had made arrangements to be in Sligo with her daughter who was sitting her Leaving Cert exams.
She said the meeting had only been scheduled by email on the day it took place, and she did not see the email until much later.
Ms O'Keeffe said she had asked last September for a pairing, for Wednesday and Thursday of last week, to allow her to be with her daughter in Sligo.
This is where an arrangement is made through the whip that two opposing politicians agree to abstain, where one member is unable to vote.
However, Ms O'Keeffe said the selection committee does not allow for such arrangements, so although she had a pairing for the day she could not be substituted on that committee.
Ms O'Keeffe added that if there had been 24 hours notice for the meeting she would have dropped her pairing and come to Leinster House for the vote.
She said that like everybody else she wanted the banking inquiry to go ahead and for there to be nine hard-working, impartial members who would do their best to get to the truth.
Elsewhere,the Dáil was suspended briefly today, after angry exchanges between Fianna Fáil leader Micheál Martin and Taoiseach Enda Kenny over the issue.
Mr Kenny insisted the Government needs a majority on the committee.
Mr Martin accused the Government of undermining the impartiality of the committee.
The Fianna Fáil leader said the Government wanted the terms of reference all their own way.