A Fianna Fáil frontbencher has said she mistakenly voted for her deputy leader in the Dáil last week.

Lisa Chambers, the Fianna Fáil spokeswoman on Brexit, told The Irish Times she sat in the seat normally occupied by Dara Calleary, who was absent at the time.

It was during the same block of votes which saw Niall Collins vote for Timmy Dooley, who was not in the chamber at the time, six times.

Mr Calleary’s vote was only recorded on one occasion he was not in the chamber, and the Mayo TD was on radio at that time.

Ms Chambers, also a Mayo TD, and Mr Calleary sit on the same row in the Dáil chamber.

Fianna Fáil deputy leader Dara Calleary was not in the Dáil at the time of the vote. Photograph: Dara Mac Dónaill/The Irish Times

In a statement, Ms Chambers said she voted in Mr Calleary’s slot by mistake before then moving to vote in her own position during a vote on an amendment on a forestry motion.

Earlier on Sunday, Ms Chambers told RTÉ she had never voted for a colleague nor had a colleague vote for her.

She told The Irish Times: “On Thursday last I inadvertently sat in the wrong seat in the Dáil during voting time. I sat in Dara Calleary’s seat, which is beside my seat. I pressed the button once in error on the first vote, no one asked me to do this and when I realised, I immediately moved to my own seat. The vote was lost by a large number so I did not inform the Teller. It was a genuine mistake and not intended. I have informed the Ceann Comhairle this evening of my error.

“I genuinely believed that this error was insignificant and when asked on RTÉ today had I ever voted for anyone else I answered no, as was never asked to vote for anyone else. For this I apologise.”

Mr Calleary said: “After participating in a live Radio Interview I returned to Dáil chamber at about 2.10pm on Thursday and voted in the remaining votes.

“I understand that Deputy Chambers inadvertently voted in my seat for the first of those votes but not for any of the remaining ones for which I was absent. She mistakenly did not correct the record on the day hence my name is registered. She has contacted the Ceann Comhairle this evening to advise him of this.”