Micheal Martin insisted that he is up to the role of Taoiseach despite conceding it will be a tough road ahead.
And the Fianna Fail politician added he was happy to be an "unpopular" Taoiseach.
Speaking on Virgin Media's The Tonight Show on Wednesday, he said: "I've been unpopular before.
"But also it's not about popularity, you know, in all the various ministries I served in, I did things that necessarily, one might have anticipated, would not have been popular. But I still went ahead and did them."
The prospective Taoiseach added that he will stay on as leader of Fianna Fail and will become Tanaiste once Leo Varadkar takes over the rotating role.
He said: "This is a government for four to five years and the rotation means I would then become Tanaiste and the Tanaiste becomes Taoiseach.
"That's the way it would work out and that's important in terms of the cohesion, durability and solidity of the government to get decisions.
"These decisions we take now and in the next year, will have to sustain over the next four to five years."
He also stressed that he had improved his relationship with incumbent Taoiseach Leo Varadkar over the recent weeks of negotiations.
Martin denied the property tax will increase and revealed the existing public service pay agreement would be honoured.
"We do need a solid, strong, effective public service in any democracy. The current agreement will be fulfilled.
"However, we will seek to negotiate a new agreement but that will be of course, in the context of very very challenging economic figures", he told host Ivan Yates.
"The number one priority facing the country from now on has to be the restoration of jobs and helping people in the private sector to get back to work."
