Profile: Former minister Denis Naughten was once tipped as a future leader of Fine Gael
Denis Naughten was often tipped to be a future Fine Gael leader before he had a spectacular falling out with the party over cuts to the health service in his native Roscommon.
Indeed, his roots in Fine Gael go deep. His late father Liam was a TD and senator for the party.
Taoiseach Leo Varadkar, marking Mr Naughten's resignation, said he had known him for more than 20 years and they were in Young Fine Gael together.
Mr Naughten (45) was first elected to the Dáil for the party in 1997.
There was a certain irony then when he became a key Independent member of the Fine Gael-led minority Government after the 2016 general election.
Former taoiseach Enda Kenny needed him to make up the numbers, despite a frosty personal history between the pair.
Mr Naughten backed the wrong horse in the infamous 2010 heave against Mr Kenny's leadership.
He was expelled from the party in 2011 in a row over the downgrading of the emergency department in Roscommon Hospital. Mr Naughten viewed it as a U-turn in a pre-election promise by Mr Kenny to maintain services there. The move did him no harm electorally and he topped the poll in Roscommon-Galway in 2016. Landing Communications, Climate Action and Environment was a good fit for Mr Naughten, a former scientist.
There has been criticism of the Government's decision not to increase carbon tax in this week's Budget.
But Mr Naughten has defended his efforts to combat climate change. He has brought in incentives for people to switch to electric vehicles and is proud of his role in the establishment of a €500m Climate Action Fund.
He also listed achievements during his resignation speech along with setting up the mobile phone task-force and his involvement in a Government initiative for online safety.
A father of four, Mr Naughten is well-liked by colleagues in the Dáil. Even those raising serious questions about his handling of the National Broadband Plan tendering process had compliments for him on a personal level once he stepped down.
It's not the only controversy that has arisen during his time as minister.
Earlier this year, he faced Dáil questions about claims he inappropriately discussed the Independent News & Media bid to take over Celtic Media Group with a lobbyist.
Mr Naughten denied wrongdoing but said taking the call from a lobbyist for INM was a "political mistake" and apologised to the Dáil.
There was also criticism over the closure of post offices this year.
He put his money where his mouth is as climate action minister, often using a Dublin Bike to travel around the city.
But in 2017 Mr Naughten had a brush with death when he was struck by a car while cycling at home two days into the new year. He suffered spinal injuries but considered himself lucky to have survived.
Since entering Government, he has frequently been asked if he would rejoin Fine Gael and always said he had no plans to do so. The events of recent days have made the chances of this happening ever more slim.