Fianna Fáil Deputy Leader Dara Calleary will be an integral voice at cabinet, despite not being a senior minister, his colleagues have insisted.
Mr Calleary was a shock omission from the ministerial ranks of Michéal Martin's government, though he will sit at cabinet as Chief Whip and junior minister at the Department of the Taoiseach.
Health Minister Stephen Donnelly, who is seen to have gotten the nod ahead of Mr Calleary, said that the Mayo TD would play an important role in the Government.
"Every minister is a national minister. The new chief whip Dara Colleary will have a significant role to play in this government. He is an incredibly competent representative who has a lot to offer.
"His voice will be front and centre in the new cabinet and balanced regional development is a core value of Fianna Fàil."
Agriculture Minister Barry Cowen told Newstalk that Mr Calleary will "have other responsibilities" in his role. He said the exact responsibilities of many members of government had yet to be finalised.
"The roles within this government are not yet complete. While the Cabinet was appointed yesterday, in relation to our own participation, there was only five seats available. I know Dara Calleary has played a huge role in working with the members and structures within the party to ensure that we were in a position to play a central role in the formation of government and we're indebted to the effort and commitment that he gave for that process.
"On reflection when you think about the role of the Chief Whip, especially in a three-party government, it does take certain qualities and skills and I think Dara has those qualities is to ensure this government lasts and that can be effective."
Mr Calleary received the backing of the cathaoirleach of his native Mayo, who said that the county had been "let down" by the Cabinet composition. Fianna Fáil councillor for Westport Brendan Mulroy described the decision as "disgraceful".
"Dara Callery has been a dedicated and loyal FF man through the years and when a lot of people went missing, Dara stepped up to the mark. He has been a team player for Fianna Fáil and has helped rebuild the party.
"He is a person who has humanity and dignity. Yesterday, Micheál Martin let Dara and us in Mayo down when he did not make Dara a full senior Minister.
"I will call it as I see it. It was a disgraceful decision and a missed opportunity for Micheál Martin to ensure delivery to Mayo. Dara there will be another day and until then you can be assured of our support."
The anger over Mr Calleary's omission had cast a shadow over Fianna Fáil's return to power after nine years. Saturday saw Michéal Martin become the 15th Taoiseach and eighth Fianna Fáil leader to also lead the country.
Mr Martin described his election as Taoiseach as "the greatest honour that any Irish person could hope for."
He said: "I am humbled by the responsibility and I pledge to work night and day with my partners in Government to realise the great potential of our nation."
Mr Martin told the Dáil that his would be a government focused on rapidly delivering jobs and paid tribute to his Cork upbringing.
"There is no time for quietly settling-in. Every minister has a substantial role to play not just in delivering the commitments for the Departments but also in the Government’s collective work.
"Every day my parents showed us the importance of supporting each other, of tough but fair competition and of the spirit of community.
"From my late father we learned not just of the great sporting achievements he saw, we learned of the characters and values of the heroes who were and remain immortal to us.
"We learned the importance of persistence, of optimism and of always understanding that Cork will soon win another double."