Michael McGrath has said he will not be part of any coup against Taoiseach Micheál Martin.
The Minister for Public Expenditure and Reform has also suggested that a controversial tax on concrete blocks will be tinkered with before it is brought into force.
Members of both Fianna Fáil and Fine Gael have hit out at the 10% levy on concrete materials announced in this week's Budget.
Mr McGrath said: "It is always the case with any tax measure that's announced in Budget Day, that it is teased out in detail over the course of the passage of the Finance Bill.
"I have been on the other side of that on many occasions, tabling amendments, working out exactly what the consequences are, and Minister Donohoe will engage with colleagues now from across Government, and indeed listen to the views of the opposition in the course of the Finance Bill."
However, speaking to the Fianna Fáil Ard Fheis he added that the State will have to fund a mica bill that could be up to €3bn.at the
"Wherever we identify a new funding source, there's always a degree of pain. So, the Government has to raise the money," he said.
Turning to the leadership of the party, Mr McGrath said: "I certainly won't be part of any coup, I think Micheál is doing an excellent job and has my full support. I've met hundreds of members here today [at the Ard Fheis] and I'm not hearing any commentary or issues being raised about leadership and people are very happy with the leadership."
Asked directly if he has ambitions to take over after Micheál Martin, he said: "There's no leadership vacancy, and I don't expect one to arise for quite some time."
It comes after Dublin Bay South TD Jim O'Callaghan told another conference that he would like to be the Taoiseach of a united Ireland.
Asked if Mr O'Callaghan was right to set out his ambitions in such a blunt manner, Mr McGrath said: "I'm not going to speak for others, you know, everyone has their own way of doing their business and setting up their ambitions and so on.
"I think that when you are serving in Cabinet and you have the privilege of being in government and have a leader, I think it is important to be fulsome in your support and my support is genuine. And I do believe he's doing an outstanding job."