It has been billed as a battle for the soul of the party.

Green Party membership has swollen over the past two years and now, perhaps unexpectedly, it is on the cusp of power and the chance to realise its policies.

Yet the moment is bittersweet with fierce debate convulsing the party as to whether the wins in the coalition deal are sufficient.

The online special convention saw passionate contributions from members and representatives, all of whom were acutely familiar with the 126 pages of the programme for government.

It has been studied closely but Green acolytes are split on its contents.

However, the core argument seems to centre on the broadly acknowledged wins in climate and transport versus what some see as serious deficiencies in social justice.

Deputy leader Catherine Martin acknowledged those shortcomings when she backed it but she also said it represented the best Green deal in the history of the country.

On the opposing side, TD Neasa Hourigan pointed to a "regressive" carbon tax model and the wrong approach to housing - she said the plans would make homelessness worse.

The debate has been summed up by former TD Mary White, who advised unhappy members to temper idealism with pragmatism.

On the pro side of that core debate are many climate action groups.

Friends of the Environment and An Taisce have lined up to praise the programme for government, albeit with some caveats.

However, proponents of a No vote insist the party ceded too much ground on social issues, including how to tackle the housing shortage and the model of carbon tax.

On the latter, the party pushed hard for direct rebates to consumers to offset planned increases but ultimately gave in to the hypothecation model, where funds are ring-fenced for climate initiatives.

Behind this is the fear of Green insiders that they will get the blame for carbon tax increases as Sinn Féin and hard left parties line up to oppose the move.

Indeed it's been dubbed the "new water charges" by some.

And already Sinn Féin, People Before Profit and others have stepped up the attacks on the Greens in the past week, carving out the battle lines for the next Dáil if this government is formed.

Within the Green Party, it is a mark of the depth of the split that opponents of the deal straddle most levels of Green elected representatives. 

TDs and councillors are divided and significantly the leaderships of one of the few all-island parties are split north and south.

Party insiders were not surprised the intervention by Clare Bailey, the leader of the Green Party in Northern Ireland, at the weekend as she had abstained on the vote on the deal.

But a majority of Northern councillors have also come out against going into government.

By now, most of the votes have been cast and it’s over to the 1,962 registered members to decide.

The formation of the proposed coalition depends on a positive result and there is no certainty about a future government in the event that this bid fails.

Whatever happens, the Green Party will immediately be plunged into a leadership contest at a time when internal rancour has spilled over.

While Greens have stressed the democratic nature of their approach, the no side has accused some of scaremongering about the ramifications of the party if it refuses to join the coalition.

That makes for a difficult official start to a leadership competition that in reality has already been at play, beneath the surface.

And it will lead to more intense debate within the party about its future direction.

For many members, there should be no choice between climate action and social justice.

However, the heated argument around the coalition deal exposes the reality that politics frequently comes down to tough choices in the face of finite resources.

This means that the next leader - either Catherine Martin or Eamon Ryan - will still be grappling with the fissures in the party and attempting to heal divisions.

And what does all this mean for the Green Party’s electoral prospects?

Its stunning 2020 result of 12 Dáil seats was achieved with nearly 156,000 first preference votes compounded by its transfer-friendly status.

However, the party’s 3,000 signed up members are a very small subset of that group, and even fewer, just under 2,000 have registered to vote on this big decision.

Yet they are the ones who are deciding whether the party should enter government, even though most who voted for them would have hoped for a Green-tinged administration.

And that means several sitting representatives could lose out in the event of a snap election.