Government Chief Whip Regina Doherty says Enda Kenny needs to be at the table when the Brexit negotiations begin.
She launched a staunch defence of the Taoiseach, after he told the Fine Gael parliamentary party he would address his future after St Patrick's Day.
Leadership hopefuls Simon Coveney and Leo Varadkar said they accepted his timeline, after Mr Kenny put down critics within his party last night.
The Government Chief Whip says the Taoiseach's experience is needed to get Ireland the best Brexit deal possible.
Ms Doherty said: "He is the most selfless man that I know, and why he wants to finish what he wants to finish has got nothing to do with legacies, I've never heard that kind of tripe to be honest with you ever to come out of his mouth.
"We're about top enter probably one of the most serious negotiating periods for this country, because out of all the 27 member states, we have the most to lose.
"It warrants the second-most important senior politician sitting round that table of 27, he is the man that I want sitting at the table."
Mr Kenny did signal that he will step down by Easter, but only after rounding on his critics and launching an attack on the camps within the party.
He made a relatively short speech at a gathering behind closed doors in Leinster House yesterday.
He stated that he wanted to go to the White House on St Patrick's Day and would deal with the issue of his leadership shortly after his meeting with the US President Donald Trump.
As expected, he provided no specific date for his departure - however, he appears to have fought off any immediate motion of no confidence.
Speaking last night, Parliamentary Party chairman and Kildare South TD Martin Heydon insisted the matter is over for now.
"A very unified part coming out of this Parliamentary Party meeting - and the thing about Fine Gael is we're a diverse group and people have different views.
"And unlike other political parties, our members fell free to speak their mind and that's not a bad thing in some respects.
"And I'm very happy after tonight's meeting that we have clarity from the Taoiseach around his position, and that we have a party that's united moving forward and the very important work in front of us".