Bertie Ahern has described Minister for Finance Brian Cowen as his "obvious successor" in the role of taoiseach.
Mr Cowen, who is deputy leader of Fianna Fáil, was promoted to Tánaiste on Thursday in the new Cabinet.
In an interview with RTÉ yesterday, Mr Ahern said his colleague has a "brilliant mind" and had "vast experience" in politics.
"He is a hugely experienced politician, and I think from my point of view he is the obvious successor in five years time or whenever," Mr Ahern said.
On yesterday's Cabinet appointments, the Taoiseach said: "I could confidently pick another 12 ministers from the backbenches and up to 35 who would make suitable junior ministers. "But you need to balance experience, ideas, cool heads, ability and new people."
Mr Ahern, who was first elected to the Dáil in 1977 and has been Taoiseach since 1997, repeated his pledge to retire from politics at the end of this Government's term of office in 2012. "That's my plan," he said.
Mr Cowen became a TD in June 1984 after the Laois-Offaly by-election that was caused by the death of his father, Bernard.
He held a number of ministries, including energy, transport, labour, foreign affairs and health before succeeding Charlie McCreevy in finance in September 2004.
He once famously described the Department of Health as "Angola" during his tenure there.
