With Sinn Féin storming ahead in the Irish electoral race, the Irish progressive movement for the first time can envisage a social democratic government, while the probability of a unification referendum on the island’s future has just become near inevitable.

In a series of polls that have been making Fine Gael and Fianna Fáil strategists increasingly queasy, Sinn Féin’s recent surge in popularity has brought it within touching distance of becoming the Dáil’s largest political party after Saturday’s general election. This result would be the first time in a century that the ruling duopoly of centre-right parties had failed to produce a victory since the end of the civil war almost a century ago.

With neither Fine Gael or Fianna Fáil willing to accommodate the possibility of Sinn Féin ministers in the Republic due to the party’s historic links with paramilitarism — despite both centre-right parties holding the mutual position that Sinn Féin has a duty to take part in the power-sharing administration north of the border — the most likely outcome remains some form of confidence and supply arrangement between Fine Gael and Fianna Fáil propped up by right-leaning independent TDs, although such an emergency government is unlikely to last longer than a few months.

This was hardly what the current taoiseach, Leo Varadkar, hoped for when he called the election in an attempt to capitalise on his handling of Brexit negotiations with the United Kingdom.

The Irish political establishment (and not a few grassroots activists) were convinced that the wave of popular fury which followed the financial crisis and eurozone-mandated austerity measures was on the wane. Indeed, in local and European elections in 2019 Sinn Féin’s vote seemed to be in freefall, losing nearly half of its local councillors and two MEPs, with pundits gleefully blaming Sinn Féin’s refusal to take its seats in Westminster as the root of the party’s electoral misery.

What this analysis failed to take into account was that – unlike in Britain, where in the aftermath of the 2015 election various strands of the radical left found themselves absorbed into the Labour party – no such process has occurred in the Republic of Ireland. In fact, the Irish progressive left is currently more fractured than at any point in its history, with Sinn Féin, the Greens, Social Democrats, Labour, the Trotskyist People Before Profit-Solidarity alliance, the Workers party, and independent socialists and populists of various stripes all running candidates across the 26 counties.

Under an electoral system like Britain’s, this would condemn the nominal ‘progressive bloc’ to perpetual opposition, but Ireland’s preferential voting system means that ideological and personal splits are less disruptive to the movement. Indeed, taken as one collective force, parties of the centre-left and left would gain 48% of the vote according to the most recent Survation poll, far outstripping either Fine Gael on 17% or Fianna Fáil on 22%.

The basis of the renewal of Irish republican fortunes is simple: the economic growth sustained since the recession has not been translated into material benefits for the vast majority of people, prompting widespread anger, while Sinn Féin has pursued a successful strategy of marrying its traditional working-class republican base with a younger cohort of professionals whose support for the anti-partionist party tends to boil down to its redistributive economic policies rather than the border question. Even Sinn Féin’s rivals have admitted as much, with Labour TDs conceding their support for housing spokesperson Eoin Ó Broin’s proposed housing programme.

Yet there remain significant challenges to the potential formation of a Sinn Féin-led government in Dublin, meaning the party is unlikely to see the full fruits of its current polling. Aside from a tendency to over-perform in opinion polls prior to elections, Sinn Féin made a decision early in the election to run a limited list of just 42 candidates – compared with Fine Gael’s 82 and Fianna Fáil’s 84 – to minimise potential losses.

As a result, some politicians and activists – most notably in the Irish Labour party and amongst some Sinn Féin activists – are mooting a move to reach out to Fianna Fáil after the election, given the party’s historic base of agrarian populism and economic protectionism, something Fianna Fáil’s leader, Micheál Martin, has increasingly pointed to as the campaign has developed, even proclaiming “Fianna Fáil is the party of the working classes” in an interview with the Irish Independent.

Arguably, this would be a historic mistake for the left. The last three times movements of a progressive bent entered government with one of the two ruling parties, the result has been electorally calamitous, with Labour experiencing an utter rout in 2016, the utter wipeout of the Greens in 2011, and the destruction of Democratic Left – a eurocommunist breakaway from the Workers’ party – after entering the rainbow coalition in 1994. Despite some short-term policy successes, and the gradual liberalisation of Ireland’s constitution on several social issues, in structural economic terms Ireland’s lack of any alternative government to the ruling duopoly has had disastrous effects for the country, most recently with the healthcare system falling into disrepair, total economic reliance on growth driven by attracting multinational corporations with low tax rates, and an overheated housing market driving a homelessness crisis in Dublin and its surrounding commuter areas.

But no matter the outcome, the result will have serious implications for politics north of the border. The potential of a Sinn Féin-led administration in the Republic of Ireland, with Sinn Féin ministers in the south sitting alongside Sinn Féin ministers from the north on cross-border committees, is a nightmare scenario for political unionism, as the party would naturally start to prepare the legislative framework for a more seamless transition to unification.

The other consequence, in a twist of irony for the Democratic Unionist party, is that now the United Kingdom is no longer a member state, the European Union ceases to be an impartial observer in Ireland. If the Republic sought to use the constitutional position of the North to delay or hamper trade talks between Britain and the EU – following the example of the Spanish government with regards to Gibraltar – very little stands in a more belligerent Irish government’s way of extracting a border poll in exchange for the progression of those talks.

Boris Johnson has already clearly shown the Conservatives’ position is that Northern Ireland’s continued alignment with the rest of the UK is far secondary to his preferred model of Brexit, and the howling of a political movement that no longer has any leverage in Westminster is unlikely to change that.

Conor Boyes is a writer based in Belfast.