Sinn Féin has surged in Ireland’s election campaign, putting pressure on centrist parties to drop their opposition to forming a coalition government with it after the election next month.

Opinion polls show sharp rises in support for the republican party before an election on 8 February, potentially edging it closer to its goal of gaining power in Dublin to push for unification between the Irish Republic and Northern Ireland.

Polls currently put the main opposition party, Fianna Fáil, on track to be the largest party in the Dáil with Leo Varadkar’s Fine Gael in second place, but suggest neither will be able to form a government without Sinn Féin’s support.

One poll gave Fianna Fáil 27% support, Fine Gael 22% and Sinn Féin 20%, with Labour, the Greens and others accounting for the rest. Another poll gave Fianna Fáil 26%, Fine Gael 23% and Sinn Féin 19%.

Varadkar’s centre-right party, in power since 2011, has slumped amid voter fatigue. Youthful, gay and the son of an Indian immigrant, the taoiseach embodies a modernising Ireland and presides over a humming economy, but flaking public services and rows over homelessness and a proposed commemoration of pre-independence police forces have tarnished his image.

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Its name can be translated as family or tribe of the Irish. A centre-right party with a socially progressive tilt. In office since 2011, first led by Enda Kenny, then Leo Varadkar, with support from smaller coalition partners. Traces roots to Michael Collins and the winning side in Ireland’s 1922-23 civil war. The party traditionally advocates market economics and fiscal discipline. Appeals to the urban middle class and well-off farmers. Fianna Fáil Its name means Soldiers of Destiny. A centrist, ideologically malleable party that dominated Irish politics until it steered the Celtic Tiger economy over a cliff, prompting decade-long banishment to opposition benches. Under Micheál Martin, a nimble political veteran, it has clawed back support and may overtake Fine Gael as the biggest party and lead the next coalition government. Founded by Éamon de Valera, who backed the civil war’s losing side but turned Fianna Fáil into an election-winning machine. Sinn Féin Its name means We Ourselves, signifying Irish sovereignty. A leftwing republican party that competes in Northern Ireland as well as the Republic. Traces roots to 1905. Emerged in current form during the Troubles, when it was linked to the IRA. Peace in Northern Ireland helped Sinn Féin rebrand as a working-class advocate opposed to austerity. Under Mary Lou McDonald, a Dubliner without paramilitary baggage, Sinn Féin has become the third-biggest party, and its vote share surged in the 2020 election. Others Partnership with Fine Gael during post-Celtic Tiger austerity tainted the centre-left Labour party. The political arm of the trade union movement, it is led by Brendan Howlin, a former teacher and government minister. The Social Democrats and Solidarity-People Before Profit are part of an alphabet soup of smaller, more leftwing parties. The Greens, wiped out in 2011 after a ruinous coalition with Fianna Fáil, have campaigned on the back of climate crisis anxiety and youth-led protests. Independent TDs have prospered in recent elections, turning some into outsized players in ruling coalitions. Rory Carroll

Sinn Féin, the political wing of the IRA during the Troubles, has meanwhile refashioned itself in the republic as a leftwing champion of the working-class and pensioners and an alternative to the Fianna Fáil/Fine Gael conservative duopoly that has taken turns ruling Ireland for almost a century.

Both the leading parties, along with the much smaller Labour, have ruled out any coalition with Sinn Féin, saying it remains beholden to shadowy IRA figures.

Varadkar has floated a grand centrist alliance between his party and Fianna Fáil, which propped up Fine Gael’s outgoing administration with a confidence-and-supply deal, but Fianna Fáil’s leader, Micheál Martin, has ruled that out.

The political establishment was “desperately” seeking justifications to exclude Sinn Féin, its leader, Mary Lou McDonald, told RTÉ radio. An effective media performer, she was expected to use a televised party leaders’ debate on Monday night to promote Sinn Féin as an agent of the change that most voters say they want.

Sinn Féin’s return to government in Northern Ireland – the power-sharing executive at Stormont revived this month after a three-year impasse – is thought to have bolstered the party’s credibility south of the border.

The retirement of former leader Gerry Adams – he is stepping down as a TD (MP) for Louth – will further distance the party from the Troubles.

However, Fianna Fáil and Fine Gael say a revelation about Sinn Féin leaders secretly consulting former IRA figures during Stormont’s “cash-for-ash” scandal shows why the party is not ready for power in Dublin. “We just don’t think that’s proper in a democratic society,” Varadkar said on Sunday.

The taoiseach also cited Sinn Féin’s opposition to a special criminal court, which sits without juries and focuses on terrorism and organised crime. Another objection is Sinn Féin’s call for a referendum on Irish unity within five years, which Fianna Fáil and Fine Gael brand as reckless.

Varadkar said, in hurling terms, that his party was three points behind, but predicted voters would return Fine Gael to power as the best manager of the economy and Brexit.

In a combative BBC interview the taoiseach talked up Ireland’s ability to harness EU solidarity and to face down British policymakers, whom he accused of not understanding Ireland. Such rhetoric boosted his ratings last year but voters are now focused on housing shortages and dysfunctional hospitals.