A green revolution is set to transform Irish politics after more than a month of high-stakes government talks delivered a series of massive "wins" for Eamon Ryan's party.
The two Civil War parties, Fianna Fail and Fine Gael, are on the brink of forming a historic coalition after making a series of concessions to secure the Green Party's support.
Now all sides face an anxious wait to see if the programme for government will be approved by the membership of the three parties.
Most in doubt is the position of the Green Party's grassroots, where a two-thirds majority is needed to get the deal over the line.
Negotiating teams from all three parties broke up in the early hours of yesterday after finishing a draft programme for government to be considered by their party leaders.
Fianna Fail's Micheal Martin, Taoiseach Leo Varadkar of Fine Gael and Mr Ryan met last night to thrash out issues such as the state pension age, plans for income tax and USC and future increases in carbon tax.
Fianna Fail and Fine Gael agreed to the Greens' demand that carbon emissions be cut by an average of 7pc a year.
A 2:1 split on public transport spending over new roads infrastructure is also part of the deal, as is a commitment to end offshore oil and gas exploration.
The position of the party's deputy leader Catherine Martin, who is challenging Mr Ryan for his job, will be closely watched as a sign of whether or not the Greens' wider membership will ultimately approve the deal.
Her supporters in the looming leadership battle have been among the most vocal sceptics of entering government with the two larger parties.
Ms Martin, who had been opposed to entering talks with Fianna Fail and Fine Gael, was silent last night, although sources involved in the talks believe she will back the agreed deal.
TDs and senators from all three parties are to examine the fine details of the proposed coalition today before their wider memberships are consulted.
The Green Party source insisted the deal represents "a strong programme for government". They added: "It contains very significant Green Party policy wins across a wide range of areas - environmental, social, housing and equality.
"I believe our members will see the real progress that can be achieved over the next five years and I think they'll support it."
Five-year 'Carbon Budgets' setting out greenhouse gas emission cuts for every sector are to feature as part of the battle against climate change.
Other environmental initiatives, such as funding of €360m a year for walking and cycling as well as a ban on single-use plastics, have been agreed.
The party's demand for carbon tax increases to €100- a-tonne over the next decade is understood to have been among the issues still being considered by the party leaders last night.
The Green negotiators were said to be particularly happy at securing a commitment to end direct provision for asylum- seekers and develop a new system with an alternative accommodation model and a faster application process.
A senior Fianna Fail source hailed measures to ramp up the supply of affordable housing as areas of the deal influenced by the party.
They said: "Our members are nervous about it, but I think we have a good deal, a deal that they can sell in their communities as showing FF policies across the country.
"There's a lot of work to be done over the next few weeks to sell it, and we'll be selling it hard to our members."
Fine Gael pointed to a new "cradle to grave" care deal that would see increased support for childcare, enhanced parental benefits and a statutory system of home-help for the elderly as key issues it was pushing for.
Tanaiste Simon Coveney said the plans in the draft document are "good for the country".
Both Fianna Fail and Fine Gael sought to take credit for plans for a major jobs and stimulus package aimed at helping the hospitality industry and small businesses worst-hit by the coronavirus crisis.
The Covid-19 pandemic is said to dominate much of the deal, particularly in the areas of health and education.
Among the other issues being hammered out were Fianna Fail's bid to delay next year's planned rise in the pension age to 67, pending a review.
They were also expected to finalise plans for income taxes and USC amid Fine Gael's demand that there be no increases and the possibility of cuts once the economy recovers.
Failing a last-minute hitch, agreement was expected on both issues.