Fine Gael TD John Deasy is planning to work in the US after he stands down from Irish politics.
Taoiseach Leo Varadkar has thanked the Waterford politician after he announced his departure.
Mr Deasy has confirmed that he will not contest the next General Election.
The 51-year-old was elected to the Dáil in 2002. His father Austin served as Minister for Agriculture in the 1980s.
John Deasy was appointed special envoy to the US in 2017, to work on the issue of undocumented Irish emigrants by the Taoiseach.
Mr Deasy said he will continue working to get a bill to extend the E3 visa scheme to Irish citizens back before US Congress by the end of the year.
Speaking to RTÉ News, he said: "Both myself and the Taoiseach want to see that Bill go back to both chambers in the United States Congress by the end of the year."
Asked why he had decided to depart now, Mr Deasy said he wanted to leave politics while he was still young enough to do something else.
"The main reason I'm retiring is because I've been working in politics for 30 years and I feel if I don’t leave now I will get too old to start something new.
"I have been planning this for a long time and I told Leo in March that I was leaving. I told him I would help in Waterford in the next General Election," said Mr Deasy.
Attention will now turn to who will replace Mr Deasy in the next general election.
In a statement today, Mr Varadkar paid tribute to him for his many years of service.
He said: "John's retirement from the Dáil will end more than half a century of service by the Deasy family; one [of] the proudest and most honourable in our political history.
"John has done stunningly effective work as my envoy to Capitol Hill informing Congress about the impact Brexit could have on Ireland and campaigning for immigration reform for Irish citizens."
However, there had been difficulties in Mr Deasy’s constituency. In June, the Fine Gael organisation in Waterford passed a motion of no confidence in the TD.
He was not at the meeting which was called to discuss the party's recent performance in the local elections.
Reflecting on three decades in political life, Mr Deasy said being in politics has been particularly difficult over the past three years.
"Politics is a very unstable livelihood at the best of times and recently because of the splintering of Irish politics it has become chronically uncertain.
"It has been difficult for people in the last three years, people have been looking over their shoulder for an election to happen. I don’t think that will change any time soon."
Looking ahead to what the future holds Mr Deasy said he sees himself working in the United States.
"The last few years have allowed me to connect with my background on Capitol Hill in the Senate so I 'm looking at maybe going Stateside at some stage."
Asked about the highs and lows of political life, Mr Deasy said the high was banning the use of hand guns in 2008.
"I never really had any dramatic lows, I have never lost an election and when you leave politics without having lost an election you count your blessings."
Mr Deasy, who married RTÉ television presenter Maura Derrane in 2005, has been a member of the Fine Gael party for 30 years.