Because of our proportional election system, Ireland is nearly always governed by a coalition between at least two political parties. The last majority, one party Government was elected in 1977, when Jack Lynch promised everything short of Nirvana to win the election, and then fell from power shortly thereafter when it became apparent that he hadn’t quite thought things through. Almost ever since, Ireland has been ruled by a succession of cosy little arrangements – Charlie Haughey propped up by Tony Gregory, Fine Gael and Labour, Bertie Ahern and the PDs, and most recently, Leo Varadkar and various independents, with the tacit support of Fianna Fáil.

The fact that we have coalition Governments means that usually, the party that you vote for does not get to implement their manifesto in full. Usually, what happens is something like this: Party A promises a 10% increase in public spending but does not get enough votes for a majority. Party B, which has promised a 10% tax cut, offers to form a Government with Party A. After some tough negotiations, the public gets a 5% tax cut and a 5% spending increase. And so, in theory, everyone is kept happy, or at least less annoyed than they might be in opposition.

The present General election is likely to see a continuation of that. Last night’s debate spent as much or more time discussing who Mr. Varadkar or Mr. Martin would go into Government with as it did discussing the state of the health service. “Who would you do a deal with?” is perhaps the single most important question, if you want to hold your politicians to account during an election.

Which brings us to the Greens. Who would they do a deal with, and more importantly, what would such a deal look like?

Climate change is not an issue that you can “do a deal” on. The Greens are explicit that if Ireland (and the rest of the world) does not cut emissions by half in the next ten years, then the very fate of the planet is at stake. How do you do a deal on that? Imagine the negotiations with Fianna Fáil or Fine Gael: “We can’t do 50%, lads, but how about 20% and a new national park in Kilkenny?” On any other issue, that might be a good deal. But how can the Greens accept anything less than their full demands be met on the climate issue? If they took a coalition deal that offered less, it would expose one of two things: Either they do not believe their own words about how essential the 50% cut is; or, more troublingly, they’re perfectly happy to risk the world burning in return for a nice seat in the back of a luxury hybrid ministerial car while it does.

Saoirse McHugh, every journalists’ favourite Green, seemed to admit as much yesterday in a promotional video for her candidacy produced by the left-wing website Joe.ie:

That video could well be entitled “no pasaran”. “I wouldn’t prop them up”, says she, in a long video in which she also advocates for a general strike and (presumably jokingly, though one never knows) the return of the guillotine for climate criminals like those in the two big parties.

So, what will happen if the Greens do, as some pundits are suggesting, come back with 10 or so seats, and the ability to grant Mr Varadkar or Mr Martin the keys to Government buildings? In some ways, it’ll be the biggest test of the Green movement in its history. We have listened, for the past number of years, to voices like Greta Thunberg telling us that the world is on fire, and that children her age may not live to see 2050. Surely the Greens simply cannot compromise and enter Government on anything but the full terms of their manifesto if they have the chance?

After all, if we believe what they say, then a compromise like that could be fatal for all human life. They’d never do it, would they?

Just you watch and see.