Veteran Labour TD Brendan Ryan has decided to stand down from the party's General Election ticket in Dublin Fingal, to allow his parliamentary assistant Duncan Smith to stand in his place.
Mr Smith recently contested the by-election and finished in third place taking 16% of the vote.
Mr Ryan said: "The recent by-election presented an opportunity for the next generation to come through, and our candidate Cllr. Duncan Smith showed the strength of the Labour Party in Dublin Fingal.
"I am confident that we can hold our Labour seat in a General Election with a new candidate and because of that I believe the time is now right for the transition to the next generation."
Mr Ryan was one of just seven Labour TDs to hold his seat in the 2016 General Election but told his local organisation in Fingal on Wednesday evening of his decision to stand down.
In a statement issued by Mr Ryan thanked his constituents, colleagues, friends and family for their support.
He said: "“It has been a great privilege and honour for me to represent the people of Dublin Fingal in Dáil Éireann for nearly nine years now, and in Seanad Éireann from 2007 to 2011.
“It was a momentous period of time that saw great change and upheaval across the political spectrum and I am proud to have played my part in that as a Labour Party representative."
“I want to take this opportunity to thank my parliamentary colleagues for their friendship over the years, and as our Whip it was an honour to work with them.
“Finally, and most importantly, I want to thank my family for their dedication and support throughout my political career. They are the unseen and often unacknowledged supporters who shoulder the burden of a political career.”
Labour Party Leader Brendan Howlin TD thanked Brendan Ryan for his years of service to the people of Dublin Fingal.
He said: “While Brendan will continue to serve the people of Fingal up until a general election is called, I fully appreciate this was a difficult decision for him to reach.
“For over a decade, Brendan Ryan has been a stalwart of the Labour Parliamentary Party and I want to acknowledge his years of service in his constituency, work he will continue to carry out up until this Dáil is dissolved.
“In his position as Whip he has played a pivotal role in the ongoing work of rebuilding our Party, and locally he has set a fine example by bringing forward new candidates and electing a new generation of Councillors for our Party.
“I know he will be determined to ensure whoever our candidate is for Dublin Fingal will be elected to Dáil Éireann, and you couldn’t ask for a more determined advocate campaigning for you.“