An election is in the cards in the United Kingdom, and that means voters in Northern Ireland are probably heading to the polls sooner rather than later.

Prime Minister Boris Johnson has called repeatedly for a snap election, and while he still needs the opposition parties to get on board, political realities might soon dictate the inevitable.

The latest opinion polls show the Conservatives leading with 27 per cent, Labour trailing with 24 per cent, followed by the Liberal Democrats (22 per cent) and then the Brexit Party (16 per cent). It is difficult to predict how an election will play out, but Labour could end up scrounging together a government with support from the Liberal Democrats and the Scottish National Party.

But the numbers are close, and it is equally likely the Conservatives form another government, this time with support from both the Democratic Unionist Party and the Brexit Party. For Labour to retain its hypothetical majority, it is very possible that it would need Sinn Fein votes to ensure the survival of a left-wing government opposed to Brexit, ultimately requiring Sinn Fein to abandon its long-standing policy of abstention from the UK Parliament in Westminster.

Read more: Sinn Fein internal elections will be real battles from now on

Brexit has been stirring speculation that Sinn Fein might finally abandon abstention in order to have a potentially decisive say on the issue since the last general election. But to those familiar with republican politics and history, it was a ludicrous suggestion. Abstention is a matter of principle. It was never up for debate.

Of course, this is well known to Labour leader Jeremy Corbyn. He was an outspoken Sinn Fein sympathizer during his early career in the 1980s and 1990s, and he repeatedly called upon the British government to relinquish control of Northern Ireland.

Corbyn has since moderated his stance and believes now that constitutional change can only occur through referendum. Still, Sinn Fein would have a natural ally in London if Labour forms the next government and Corbyn is installed as prime minister, but the Labour leader understands that getting Sinn Fein to actually take its seats in Westminster and vote alongside his government would require him offering nothing short of a referendum on Irish unity.

Sinn Fein would face the ultimate dilemma. Abstention has been one of the party’s most cherished ideals since it was first adopted in 1908. What started as a political tactic transformed into a moral issue after the Easter Rising, and republican doctrine now states that it is what gives the entire movement legitimacy.

For that reason, debates over ending abstention have had a profound impact on the history of the movement, even at times where it seemed clear that participating in constitutional politics was the best way forward.

The decision by pro-Treaty republicans to accept British terms and sit in the dominion-style Dublin Parliament at the end of the War of Independence in 1921 led immediately to the Civil War the following year, and the republican left’s decision in the 1960s to drawdown the armed campaign and contest elections led to the vicious republican feuds of the 1970s.

Gerry Adams and his allies rightly deserve praise for successfully convincing the mass of the republican movement to end abstention from the Irish Parliament and the Northern Ireland Assembly, but even they understood they could not secure a settlement attractive enough to convince Republicans to allow their representatives to take their seats in Westminster. It was a red-line issue.

The question now is, would Sinn Fein, faced with the choice between principle and policy, abandon abstention in exchange for a historically unprecedented opportunity to achieve unity?

The Republican leadership is certainly not shy to ditching principle, but the risk here would be incalculable. A referendum does not guarantee unity, and current demographics will almost certainly prevent any dramatic shift in either direction.

Protestants still compose approximately 48 per cent of the Northern Irish population compared to Catholics’ 45 per cent, and while a recent Tory poll does show a slight preference for unity among the voting public, other recent polls suggest the picture is more ambiguous.

If the referendum did fail, the Good Friday Agreement bars another one from occurring for at least 7 years. Republicans might jump the gun this time, lose the vote, and then watch a more opportune moment pass in the event of a possible no-deal Brexit.

This doesn’t even consider how loyalists would react to a unity referendum. Although republicans would characteristically ignore their attitudes, their historically militant way of opposing political change in Ireland would doubtlessly have severe consequences for both the campaign and its outcome.

For that reason, even if the referendum passed with a bare 50%+1 majority, most observers agree that the nature of Northern Irish society makes such an outcome unworkable, requiring something closer to a two-thirds majority to be effective.

Perhaps most important for Sinn Fein, a unity referendum would put the future of the party at grave risk. Compromising on principle is no easy sell, but it would prove worthwhile to most supporters if it delivers the goods in the long-run.

If it does not, Sinn Fein will be seen to have naively sold out to the British establishment, destroying its credibility as a republican party, likely ending the careers of all (or at least most) of its leaders, and heralding a period of political uncertainty for the nationalist community that could set it back decades.

But it would have to get there first. A significant portion of the movement would split and renounce their loyalty to Sinn Fein before the referendum even took place. No offer, they would say—not even the republic itself—is enough to justify forswearing principle. This would remain true even if a successful referendum was a virtual guarantee.

The rewards, of course, would be historic. Sinn Fein would enter history as the organization that finally drove the British completely from Ireland, and Gerry Adams would take his place in the pantheon of national heroes. Many in the nationalist community would feel that the crimes of the Provisional IRA were absolved, and Irish republicanism would have finally reached its definitive end.

A votes-for-referendum offer from Labour to Sinn Fein would arguably be the most momentous decision any nationalist politician has faced in the last two centuries, but the possibility is real and both sides should begin to weigh the costs, risks, and rewards. Regardless of how the referendum turns out, its outcome will impact the futures of Northern Ireland, Britain, and the Republic of Ireland for at least a generation.

Read more: Judge throws out case alleging Gerry Adams linked to Jean McConville killing

This article was submitted to the IrishCentral contributors network by a member of the global Irish community. To become an IrishCentral contributor click here.

Sinn Fein campaign for Irish unity.