Sinn Féin is to stand aside in three Northern constituencies in December's general election and has urged its voters to back other candidates who support remaining in the European Union - including the independent unionist Lady Sylvia Hermon - to help defeat the pro-Brexit DUP.
It is the latest of the North’s parties to declare that it will not run in certain constituencies in order to give another party the best chance of being elected. Of the North’s five main political parties, only Alliance has said it will not enter into any type of pact with another.
Why has this happened?
According to the parties, it is because of Brexit. Each of them have referenced the particular circumstances of this vote, with Sinn Féin leader Mary Lou McDonald describing it as a “once-in a generation election” where the “stakes are very high”.
She said Sinn Féin, therefore, is “asking people to come out and vote for those pro-remain candidates” as it is “the right and progressive thing to do”.
The SDLP spoke of an "extraordinary decision" for an "extraordinary election", saying its "first priority is to elect pro-remain MPs to vote against Brexit and Boris Johnson but removing pro-Brexit MPs in Belfast is also critical".
For the UUP's leader-elect, Steve Aiken, his earlier decision to run a candidate in North Belfast attracted vocal opposition from unionists in the area, not least from his own party. A police investigation is underway into threats, including some from loyalist paramilitaries, made against UUP members and staff.
It was against this backdrop that Mr Aiken changed his mind, and the UUP now finds itself in the position of campaigning to remain in the EU yet calling on its voters to support pro-Brexit DUP candidate Nigel Dodds.
Mr Aiken said the UUP was "a party which believes first and foremost in the Union" and that it was better to elect a DUP candidate than to "facilitate the election of an abstentionist Sinn Fein MP".
Yet as always in politics, there is much pragmatism. None of the parties had a realistic chance of winning in any of the constituencies they have opted not to stand in.
What does this really mean?
In North Belfast in 2017, Dodds held the seat for the DUP with a reduced majority of some 2,000 up against the challenge of Sinn Féin's John Finucane. The SDLP's withdrawal will help his chances, but even with his own vote from last time and the 2,000 votes from the SDLP candidate, Finucane still comes up 23 votes short of Dodds' 2017 total. Both sides are likely to go all out to maximise turnout in what looks to be a very close race.
The payoff for the SDLP is likely to come in South Belfast, where Claire Hanna, a popular MLA, appears well placed to unseat the DUP's Emma Little-Pengelly. She defeated the former SDLP leader Alasdair McDonnell, who had held the seat since 2005, in 2017 with a majority of about 2,000 votes. Sinn Fein's Máirtin Ó Muilleoir polled some 7,000 votes then, and a share of these should take Hanna comfortably over the line.
The nationalist parties' withdrawal from East Belfast will make little difference in the race between the sitting MP, the DUP's Gavin Robinson, and the Alliance party leader and MEP, Naomi Long. Long was the constituency's MP from 2010-15, but was some 8,000 votes behind Robinson in 2017. The 894 and 167 votes polled by Sinn Féin and the SDLP respectively will provide little by way of a boost.
Lady Sylvia Hermon has been the North Down MP since 2001. She was originally an Ulster Unionist, but left the party in 2010 to become an independent Unionist. As Sinn Féin do not take their seats, since 2016 she has been the only pro-Remain MP at Westminster. With a majority of about 1,000, she faces a tight race, and again the absence of Sinn Féin and the SDLP - who polled less than 1,000 votes between them in 2017 - may make little difference. There is speculation that the DUP will seek to make political capital out of Sinn Féin's endorsement of her candidacy, and that it may do her more harm than good.
What about the bigger picture?
Who knows what the breakdown of parties may look like come 13th December, but Northern Ireland appears set for certainly the most interesting general election for some time.
The DUP currently holds 10 seats and Sinn Féin seven, with the remaining constituency represented by Lady Sylvia.
The SDLP will be hoping to regain a presence at Westminster by retaking not just South Belfast, but Foyle, which it narrowly lost to Sinn Féin in 2017.
While little is certain, even if just one seat changes hands - the most likely being South Belfast - it would see the leave-remain balance swing from 10-8 to 9-9.
It would bring the unionist-nationalist breakdown among MPs to 10-8; if Finucane takes North Belfast, it would be 9-9, and the DUP would no longer be the largest party.