In 2006, the Green Party of Northern Ireland – a standalone party within the UK – voted to become a regional branch of the Green Party of Ireland.
It remains a "sister party" of the Greens in Scotland, England and Wales, with which it formed a single UK party before an amicable demerger in 1990.
Only Sinn Féin has a comparable multi-jurisdiction existence but only the Greens recognise all the jurisdictions in which they operate, making them a uniquely crossover brand. The variable geometry of their constitutional positioning is ingenious and at first sight might appear to explain how they attract support from all Northern communities. The more complicated truth is the Greens never explain their British and Irish dichotomy and that careful vagueness is what allows them to win voters from unionist and nationalist backgrounds.
It is a complicated picture for such a small political force, although complicated little parties can capture media attention and public imagination
The all-Ireland nature of the Green Party is even more obscure in the Republic. It made no impression when the Greens were last in office from 2007- 2011 and it continues to go unmentioned in current coalition talks.
Yet there are reasons to believe this time should be different. Sinn Féin has become the main opposition in the Republic and unaligned voters have become the decisive electoral bloc in Northern Ireland, with the Greens making up a significant part of that bloc.
If they join a new Irish government their duality will come under scrutiny from within and without, North and South.
It is a complicated picture for such a small political force, although complicated little parties can capture media attention and public imagination.
The Northern Ireland Greens are, in many respects, indistinguishable from the other four regions of the Irish Greens. Members and delegates have the same powers and representation as everyone else in party structures and at party conferences.
Key votes have to pass by a two-thirds majority and Northern Ireland accounts for perhaps a quarter of members, so it would not take much to muster up a Northern-led veto.
This could be demonstrated shortly, as a two-thirds vote will be required to enter a Dublin coalition and joining Fine Gael and Fianna Fail is not believed to be popular with Northern members.
The basic unit of organisation in the party is the constituency, not the region, so at that level the border disappears. The Green Party of Ireland’s constitution describes itself as covering “constituencies of Dáil Éireann or the UK parliament” – a line many Southern voters might finding striking.
However, any region “outside the Republic of Ireland” can appoint its own decision-makers without central approval, in effect granting a high degree of autonomy to Northern Ireland. In short, the North gets to control itself and have a major say over Southern and all-Ireland policy as well.
A challenge for the Greens if their all-Ireland nature comes to wider notice will be retaining their unaligned image with Northern voters.
Green parties have a close history across the UK and Ireland but this is rarely mentioned today and it would be a strained effort to portray it as an east-west counterpart to the North-South Irish relationship. The Greens are irrelevant in Britain outside Scotland, where they prop up a nationalist devolved government and endorse a second independence referendum.
Attention in the Republic has been focused on the Green Party’s 17 questions for coalition partners, none of which mentioned Northern Ireland, a united Ireland, the Border or even Brexit.
However, the party’s 2020 election manifesto does contain a section on Northern Ireland, with a single but profound policy demand, acknowledged as coming from “our elected representatives in Northern Ireland.”
That policy is reform of Stormont’s powersharing arrangements, replacing mandatory coalition with voluntary coalition and official opposition. An executive and programme for government would be agreed by inter-party negotiations followed by a two-thirds vote of the whole assembly, rather than a forced marriage led by the largest unionist and nationalist parties and subject to unionist and nationalist vetoes.
The manifesto says this would be such a fundamental change to the Belfast Agreement it would need to be part of a wider programme of political reform, before being put to a referendum.
While a referendum is implausible, the proposed Stormont reforms are increasingly part of mainstream debate in Northern Ireland due to the rise in unaligned voters. This has mostly come from the Alliance surge but the Greens also made notable gains last year in council elections. The combined unaligned vote has reached 20 per cent, with unionists and nationalists both consigned to minorities. Powersharing was not designed to reflect this and will need major adjustment unless the trend reverses.
If Stormont reform is the only Northern Ireland policy of the only all-Ireland party in the next Irish government, that would deserve to have some influence.
If it turns out to have no influence, that would send its own signal about all-Ireland politics. In either event, Northerners at least will be watching.