Climate Action Minister Eamon Ryan vowed to unite the Greens and "play hardball" with Fianna Fáil and Fine Gael in Government after he was narrowly re-elected as party leader last night.
Mr Ryan beat his deputy leader, Catherine Martin, by just 48 votes on a day when a number of high-profile members, including former Dáil and European candidate Saoirse McHugh, quit the party over its decision to go into Government last month.
The tight result may also cast doubt on whether Mr Ryan can serve a full term as party leader before the next election.
He said last night he was open to considering his leadership when Fianna Fáil and Find Gael rotate the office of Taoiseach in December 2022, adding he isn't "obsessive" about his position.
Reflecting what has been a divisive debate over the Greens' decision to enter coalition with the Civil War parties, Mr Ryan won with 994 votes (51pc) to Ms Martin's 946 votes (49pc) on a turnout of 67pc.
Speaking after the result was announced, Mr Ryan said it had been a "very close vote, couldn't have been closer" and that the Tourism Minister could easily have won.
Asked about Ms Martin's comments during the campaign that she would provide "a credible threat" to walk out of government if Green Party policies were not being delivered, the Dublin South TD said: "I think there is a crisis, that we have responsibilities, if we can, [to] help address it. I can play hardball too.
"I was there last night negotiating with our partners in government and that's part of a respect for politics where you can still have differences but you can hold the line and then say, 'no', on this issue or whatever issue… it isn't one or the other, I think it's a bit of both."
Amid a raft of resignations from the party in recent days, Ms Martin urged members to get behind Mr Ryan while calling on her Cabinet colleague to reform the Greens' internal structures to deal with allegations of bullying that have been made in recent weeks.
Mr Ryan acknowledged it had been a tight outcome. "It was a really close result. There are no two ways about that. The result could have gone either way. I will reflect on that," he said.
Ms Martin said the Greens "were stronger as a party" for having had a leadership debate and contest. She said Mr Ryan was strengthened by his mandate, and added: "I ask all members to fully and actively support you as leader."
The Dublin Rathdown TD said there was no shortage of things in the party that needed change. "I know you will listen to the frustrations and concerns that have been expressed and you will work with all of us to unite the party as we go forward," she said.
She said the party needed structural and cultural change to "unite and heal the divisions" that emerged in recent months.
Ms Martin said the "most important thing we can do is stay together, stay united".
She said she would consider a future leadership bid, given the tight nature of the result and signalled her intention to run for re-election as deputy leader in October.
"I am always aware as a woman in politics, that I should never say no because I am always aware that somewhere out there a young girl is watching TV," she said. "So I would never say no to running for leadership or for office, because I want all girls, all women to know that the door is open. And sometimes in politics, you lose and sometimes that inspires you to run again."
She said the party had to examine why it had lost "some very, very good members" and that reform was needed to ensure that members feel valued. "Why are we losing good people, and what can we do to change that? … Maybe we have to reform the party in some way," she said.
Mr Ryan said he "deeply regretted" anyone leaving but the door was always open for them to return. He said he was open to the possibility of a co-leadership of the Green Party because there is an "absence of hierarchy in the style of our leadership".