Bertie Ahern described the former Fine Gael leader as a "brave, kind and honest man"
Flags at Leinster House and Government Buildings are flying at half-mast in honour of former Taoiseach, Liam Cosgrave.
Mr Cosgrave died last night at the age of 97.
This afternoon normal business in the Dáil has been suspended to be replaced with statements on the former Taoiseach's service to the state.
Yesterday evening the President Michael D. Higgins and the Taoiseach Leo Varadkar led the tributes to a man who devoted his life to the service of Ireland.
On The Pat Kenny Show this morning former Fianna Fáil Taoiseach Bertie Ahern said Mr Cosgrave was a brave, kind and honest man:
“He was a strong, resilient person,” he said. “He was a nice man; he wouldn’t have maybe long conversations with you but he was witty, always had very nice remarks to make about things.
“I think he will be remembered as a very good person; a very good Irishman who served his country for a long, long time.”
The flag flies at half mast at Government buildings as a mark of respect to former Taoiseach Liam Cosgrave pic.twitter.com/TvqE8bW7L3— MerrionStreet.ie (@merrionstreet) October 5, 2017
Born in 1920, Mr Cosgrave was first elected to the Dáil in 1943. He became Fine Gael party leader in 1965.
He was elected Taoiseach in 1973 as head of a coalition government with the Labour Party.
His four year term lasted until 1977 when Fianna Fáil swept to a landslide victory under Jack Lynch.
On Newstalk Breakfast, The Minister for Justice Charlie Flanagan said Mr Cosgrave was a “towering figure of my youth.”
“I suppose his life and his tenure in politics can be summed up as somebody who always put the security of the state first and the safety of its citizens,” he said.
“Always showed loyalty to the institutions of the State – be they the courts, the Army or the Garda Síochána.”
Former Fine Gael leader Alan Dukes says he will be remembered for his role in the security of the state:
“The other thing he will be remembered for in many ways is the fact that he is, I think, the only Taoiseach who ever voted against his own government on a major issue,” he said.
“That was on the contraception issue in I think 1973.
“Although he had very firm convictions himself; he knew that other people didn’t necessarily agree and that didn’t stop him working with them.”
Former Justice Minister Alan Shatter says he was dedicated to the good of the country:
“He stood firm, at a time of great difficulty, against the IRA; defended the institutions of the State and I think that we all owe him a debt of gratitude.”
Fine Gael MEP Brian Hayes said his death marks the end of an era for many people around the country:
“I was only with him at the end of August, with my two sons we went to see him in Tallaght Hospital,” he said.
“You could see he was coming close to the end but he was as inquisitive as ever – wanting to know how young Leo Varadkar was doing and what his view on the party was and asking questions.”
Mr Cosgrave’s father WT Cosgrave served as the first President of the Executive Council of the Irish Free State from 1922 to 1932.
While the position of Taoiseach had yet to be formally created, he was the first elected head of government in an independent Ireland.
Mr Cosgrave’s family have yet to confirm his funeral arrangements - but all former Taoisigh are entitled to a State funeral.
His wife Vera died in September of last year. He is survived by his three children - Mary, Liam Jr and Ciaran.