The Tánaiste and Minister for Finance, Brian Cowen, is the only candidate to succeed Bertie Ahern as leader of Fianna Fáil.
The 48-year-old TD for Laois/Offaly will formally be declared the seventh leader of Fianna Fáil at a special meeting of the parliamentary party on Wednesday morning.
In a statement, Mr Cowen said: 'I am deeply honoured by the confidence shown in me by the members of the Parliamentary Party.
'It is a reflection of the support of the wider Fianna Fáil membership throughout the country.
'I am grateful for that overwhelming endorsement of my candidacy for the leadership of the party at this time.'
Already seen as Mr Ahern's automatic successor, he will take over from Bertie Ahern on 6 May.
One of his first tasks in office could be a cabinet reshuffle to fill the vacancy left by his own departure from the Department of Finance.
Following that, he faces into a tough period as leader with the Lisbon Treaty referendum, a slower economy and next year's local and European elections.
Mr Cowen confirmed his candidacy yesterday after his nomination was proposed by Minister for Justice Brian Lenihan and seconded by Minister for Agriculture Mary Coughlan.
Mr Cowen said he had no problem with intense media scrutiny of his public duties but added that he had strong views about legitimate boundaries which could not be crossed in the coverage of private and family life.
Fine Gael leader Enda Kenny has warmly congratulated Mr Cowen.
In a statement, Mr Kenny said: 'I wish Brian Cowen and his family well on a personal level as it now is confirmed that he will be elected unopposed as the new President of the Fianna Fail Party.
'Leading your party is an honour that few people get to experience and, speaking from personal experience, it brings a whole series of new challenges and pressures.
'I look forward to facing Brian Cowen across the Dáil chamber and meeting him on the electoral trail in the coming months and years.'