The Education Minister has denied that he is being pushed out of government - saying he is stepping down from Cabinet of his own accord.
Ruairi Quinn says he is retiring after the re-shuffle.
His longtime party and Cabinet colleague - Pat Rabbitte - says he does not believe the Education Minister was forced out.
There had been speculation surrounding the futures of both ministers in recent weeks, ahead of the Labour leadership vote.
But Minister Pat Rabbitte says the decision by Ruairi Quinn is his own after years of public service.
Mr. Quinn says it is time to make space "for the next generation" and denied he is quitting before being pushed.
Deputy Quinn (68) has also announced he will not contest the next general election.
Minister faces press pack @labour tweeted a picture of the resignation from the Minister's own point of view
A long career
The former leader of the Labour party has served in the Department of Education since the 2011 general election and has previously been in government as Minister for Finance and Minister for Enterprise and Employment.
He has also served as Minister for Public Service, Minister for Labour and Minister of State for the Environment.
Minister Quinn has been a public representative since 1974.
Before entering public life, Ruairí Quinn was an architect and town planner.
Colleagues have been reacting on Twitter:
Rúraí Quinn has been in the Dáil since I was 2 years old
— Peadar Tóibín (@Toibin1) July 2, 2014
I am very sorry to learn that Ruairí Quinn is leaving as Minister for Education. He has been an excellent... http://t.co/xNIFNXtVGI
— Seán Sherlock TD (@seansherlocktd) July 2, 2014
Very difficult to see one of your political heroes depart the ministerial stage. Ruairí #Quinn's legacy will be as a reformer & statesman.
— Aodhán Ó Ríordáin TD (@AodhanORiordain) July 2, 2014
.@labour A friend & mentor, I'm sad to see Ruairi Quinn exit the political stage. A modernising & liberalising force in Irish society.
— Gerald Nash TD (@geraldnash) July 2, 2014
It has been a pleasure to work with @RuairiQuinnTD for the last 2 decades. He will be a huge loss to Irish politics pic.twitter.com/UeMh4yT4HA
— Kevin Humphreys (@KHumphreysTD) July 2, 2014
It has been an honour to work with @RuairiQuinnTD, a fine politician who never lost his zeal for real and lasting change. I wish him well.
— Ciaran Cannon (@ciarancannon) July 2, 2014
I've always found Ruairí Quinn to be a decent & honorable constituency colleague. Wish him & his family the very best for the future
— Lucinda Creighton (@LCreighton) July 2, 2014
Not all of Minister Quinn's colleagues had praise for him though:
“@minihanmary: Quinn will also not seek re-election at next General Election” neither will my dog @MingJulie and for a reason. #NoChance
— Luke Ming Flanagan (@lukeming) July 2, 2014
You can hear the Minister's full speech here:
