Trouble is brewing for Labour in Northern Ireland, after local members there have voted to defy the party and field candidates in the upcoming Stormont elections. Despite ostensibly being a UK-wide party, Labour has long held a policy of not running candidates in Northern Ireland, arguing that they do not want to split the centre-left Catholic vote. Instead, it asks voters to support the local Social Democratic and Labour Party which it sees as a “sister party” owing to its left of centre ethos and the fact that SDLP MPs informally take the Labour whip in Westminster.

The policy has always been deeply resented within the Northern Irish branch. Many local members feel abandoned by Labour and that the policy reflects a party which has no real interest in or commitment to Northern Irish issues. Other British parties including the Conservatives, the Greens and Ukip field candidates in the province. However, the Lib Dems take a similar approach to Labour and don’t field candidates but instead ask local supporters to vote for the liberal, right of centre Alliance Party.

At a recent meeting in Belfast, more than a hundred members of the Labour Party in Northern Ireland voted to rebel against Labour HQ and put in motion plans to run in the Northern Irish May 2016 elections.The proposed motion stated that the local contingent would put in motion plans to: “Prepare and train members who would be suitable candidates; Establish a fighting fund to pay for offices and staff; Prepare a political programme to put to the electorate; Alert the National Executive (NEC) and the Party leadership to the evolving political situation in Northern Ireland and engage with them in the process of promoting Labour’s challenge to the sectarian status quo.” It was passed unanimously.

Tensions between the Northern Irish and mainland elements of the party have existed for decades but have recently become exacerbated under the new leader and recent developments in local politics. Given Corbyn and John McDonnell’s perceived support for the IRA’s “armed struggle” and for Sinn Féin, the pair are viewed with disdain by many Northern Irish members who see the pair as lacking credibility or authority on Northern Irish politics. Similarly, during the political crisis in September which saw Stormont teeter on the verge of collapse after unionist politicians temporarily pulled out of the power sharing structures, Labour showed little interest or leadership and scarcely commented on the issue.

Furthermore, Labour’s endorsement of the SDLP as a “sister party” is becoming an increasingly strained claim. The nationalist party is perceived locally as representing only the Catholic community, alienating Protestant Labour supporters. The SDLP are also vehemently anti-abortion, in stark contrast to Labour’s pro-choice policy. The Belfast High Court last week ruled that Northern Ireland’s abortion ban is a breach of human rights legislation, meaning that in asking its supporters to vote for the SDLP, Labour is asking people to vote for a party which is seen as actively working to breach human rights law. Similarly, the SDLP’s support of Northern Ireland’s segregated education system which sees Protestant and Catholic children educated in different schools is viewed uncomfortably by Northern Irish Labour members who say the system is sectarian and divisive.

The party’s British wing has yet to respond to the news of the branch’s decision. The rebellion represents a significant challenge to Jeremy Corbyn’s authority. If Labour refuse to allow them to contest the election, it is possible that the Northern Irish branch will break off from the UK wide party and form a separate party. If this happens, it will be the first major break within the party under Corbyn’s leadership.

It would also mean that Labour could no longer claim to be a party that represents the United Kingdom, but rather only Great Britain. This plays into the Conservatives’ claims to be the only party representing “one nation” politics and furthers the idea that Labour is a party based around the Westminster bubble. After Labour’s near annihilation in Scotland, the party will be keen to maintain its credentials as a party with relevance in the regions.

With just five months to go until the Stormont election, the issue is not one that Labour can ignore any longer but one which they will need to urgently address. The Northern Irish branch are currently inviting local people to come forward as potential candidates and describe themselves as “snowed under” with interest. Labour’s neglect of and disinterest in Northern Irish members for decades means that many issues have gone unresolved and rebellious intent has been left to embed itself deeply. Now that the branch have broken ranks after decades of frustration and inaction, it may be too late for Labour to stop the momentum without major dissent and a fractured party.