Niall Collins has become the latest high profile Fianna Fáil TD to oppose coalition with Sinn Féin.
He has added his voice to Jim O'Callaghan and Anne Rabitte.
He had this to say when he was asked were there any circumstances Fianna Fáil should talk to Sinn Féin.
"Absolutely not," he said when asked if he approved of an FF-SF government. "We have taken a decision as a party, that decision still stands.
"When we meet tomorrow as a parliamentary parties, I imagine that decision will be re-affirmed. That's just my personal view in relation to it."
Sinn Féin, who got the largest popular vote in the new Dáil, has kickstarted the race to form a new Government via “constructive” meetings with the Green Party and People Before Profit.
Following an early-morning meeting with Green leader Eamon Ryan, Sinn Féin president Mary Lou McDonald said the discussion had been “useful and constructive”.