It's not that there is open hostility towards Eamon Ryan within the Green Party. Most reasonable members accept Ryan has done an admirable job leading the party from the depths of despair after the financial crash to the historic highs of the last general election.
However, they believe he has served his purpose and the time has come to step aside.
Catherine Martin's role in the Green Party's resurgence has gone somewhat unnoticed to the wider public, but her supporters say she is the real driving force behind the party's revival.
Behind the scenes over the past 10 years, she has quietly developed a reputation for being a strategic political thinker and a hard grafter.
She has a strong level of support at the grassroots level and is widely expected to put her name forward for a leadership contest once government formation talks conclude. Those urging Martin to take on Ryan say the party needs a more commanding figure leading the organisation if it is to go into government with Fianna Fáil and Fine Gael.
They worry that Ryan is too zealous about entering government and will do so at any cost to the party. The Green Party leader would argue you are better off inside than outside the tent if you want to effect change.
Some claim his bounding optimism about entering into coalition is "both a gift and curse". They fear he is blinded by his desire to return to ministerial office and is not looking around corners.
"He should have approached the talks with more scepticism and realised we should be going in with the strongest hand possible," a source said.
Martin is seen as the more pragmatic and less ideological of the pair. Supporters say she sees the need to expand the party beyond climate issues and embrace bread-and-butter political issues such as health and housing.
She is also credited with upskilling a new breed of Green recruits on the hand-to-hand combat of campaign canvassing. She has spent years travelling the country teaching new members how to win over voters on doorsteps.
Supporters say she was also instrumental in signing up young members in universities. Her work on female empowerment, including setting up the first Oireachtas women's caucus, is also a key driver behind her support.
Backers paint a picture of Martin being the engine in the party while Ryan acted as front-of-house. Those who want Ryan to step aside are frustrated with his media and Dáil performances. They say he has become "increasingly gaffe-prone" and is alienating rural voters with comments about salads and bans on cars.
They say Martin, a Co Monaghan native, is more in tune with the needs of rural communities and is a more considered performer in both the Dáil and media.
Her attack on Fine Gael deputy leader Simon Coveney over his comments on reducing emissions might not support this claim, but it did highlight her opposition to entering government talks.
She has since said she is dedicated to the talks and her backers say her successful election as leader will not necessarily mean the party will pull out of negotiations with Fianna Fáil and Fine Gael.
Martin's career progression over the past decade has been deliberate and steady. In 2011, she was elected deputy leader of the Greens at the same time Ryan succeeded John Gormley as leader.
Martin wasn't an elected representative at the time but was elected as a Dún Laoghaire-Rathdown councillor in the 2014 local election.
Two years later, she took a Dáil seat in the 2016 general election, standing in Ryan's old constituency of Dublin South, which had been renamed Dublin Rathdown.
Ryan moved from his constituency to Dublin Bay South and also secured a Dáil seat.
In 2016, the two-TD team were briefly involved in government formation talks but ultimately pulled out.
Over the past four years, the Green Party became an attractive outlet for disenfranchised young people who detested the establishment parties and were nervous of Sinn Féin and the far left.
As the world's economy bounced back after the financial crash, climate change became a more prominent political issue.
It meant a fair wind for the party, which returned to the Dáil with 12 TDs after the election on February 8.
After months of fractious internal debate, the party is now the king-maker in government formation talks.
Martin voted against the talks but now leads the negotiations. As leader, Ryan has been keeping a close eye on the talks and has even been showing up to some of the sessions, while also keeping in contact with Leo Varadkar and Micheál Martin.
Nominations opened on Wednesday and with all eyes on Ms Martin she issued a statement saying she would give "serious consideration" to contesting the leadership but only after government formation negotiations conclude. However, on the same day, Green members anxious to see Martin succeed Ryan flooded party headquarters with nominations for her to run in a contest that could be months away.