Taoiseach Bertie Ahern, who was a constituency colleague in Dublin Central before Mitchell lost his seat in the May general election, described him as an “outstandingly dedicated servant of the people who elected him”.
Mitchell had “fought against the odds all his political life” but had succeeded because of unstinting hard work, Ahern said.
First elected to Dublin Corporation in 1974 and to the Dail in ’77, Mitchell had been suffering from cancer. He had received a liver transplant two years ago.
At the aged of 29 in 1976, he became the youngest lord mayor of Dublin in its 800-year history.
He proved a great survivor in politics, having been forced to move constituencies five times. At the height of his political success in the 1980s, he brought in three of five TDs in the former Dublin West constituency.
He served as minister of transport, post and telegraphs, justice and communications during two Fine Gael-led coalition governments. He was defeated by Michael Noonan when he ran for the leadership of the party last year.
As chairman of the powerful Oireachtas public spending watchdog body, the Public Accounts Committee, he was widely praised for his handling of the 1999 inquiry into the DIRT tax evasion scandal.
Fine Gael leader Enda Kenny described Mitchell as a “conviction politician” who had served his country, people and party for 25 years with “unfailing courage, passion and integrity.”
His brother Gay is Fine Gael TD for Dublin South-Central. He is survived by his wife, Patricia, two sons and three daughters.