Sinn Fein on Sunday demanded to be part of the next Irish government after early results indicated it secured the most votes in an election its leader Mary Lou McDonald called a ballot box “revolution”. The former political wing of the Provisional Irish Republican Army, which has turned itself into the main left-wing party, secured 24 per cent of first-preference votes, almost doubling its share from the last election in 2016, early results showed. That put it narrowly ahead of Fine Gael, the party of Prime Minister Leo Varadkar, and centre-right rival Fianna Fail, breaking Ireland’s century-old centre-right duopoly. Exit polls suggest it will be Ireland’s closest election in many years. “It seems that we have now a three-party system,” Mr Varadkar said at the counting centre for his Dublin West constituency. “That is going to make forming a government quite difficult.” But Sinn Fein will probably fall behind at least one of its rivals in seat numbers because it stood far fewer candidates and is unlikely to become more than a junior partner in a government. “This is certainly an election that is historic,” Ms McDonald said. “This is changing the shape and the mould of Irish politics. This is just the beginning.” She said Sinn Fein would talk to all parties about forming a government and that others should do the same. Ms McDonald said she had started speaking to smaller left-wing parties before holding discussions with the two main parties. “I do not accept the exclusion or talk of excluding our party, a party that represents now a quarter of the electorate, and I think that is fundamentally undemocratic,” she said. Fine Gael and Fianna Fail, who have between them led every government since the Republic of Ireland was founded, ruled out a coalition with Sinn Fein before the election. But although Mr Varadkar repeated his rejection because of “principle and policy”, Fianna Fail leader Micheal Martin declined to repeat earlier refusals to consider a coalition with Sinn Fein. Mr Martin said only that there were significant incompatibilities on policy. “Our policies and our principles have not changed overnight,” he said. “But what is important is that the country comes first.” Sinn Fein’s surge in popularity may be seen as a vote for change or even a protest vote. But Ms McDonald disputed this, saying the result was “historic in proportions” and that Saturday’s vote was “just the beginning”. Many young voters have been attracted to the party because of its promises to invest more in public services. Sinn Fein has moved on from the long leadership of Gerry Adams, the face of the Provisional IRA’s war against British rule in Northern Ireland in which 3,600 people were killed before a 1998 peace deal. Irish tricolour flags were flown at a Dublin count centre as Sinn Fein supporters were led in a chorus of the Irish rebel song <em>Come out ye Black and Tans</em> by a politician jailed for possession of explosives in 1981. Opponents of Sinn Fein say its high-spending promises and pledge to increase taxes on the wealthy would discourage the foreign multinationals that employ one in 10 Irish workers. But some parties have praised detailed policies such as a proposed rent freeze and the large-scale building of houses by the state to tackle problems with the cost and availability of housing. Fine Gael, in power since 2011, was in third place on first-preference votes, with 30 of 39 seats counted. Mr Varadkar said it was not certain that his party would have more seats than Sinn Fein. Fine Gael’s focus on the fastest-growing economy in the EU and success in negotiating a Brexit deal that avoided a “hard border” with Northern Ireland, with border checks reinstated, failed to capture voters more focused on health and housing. Mr Varadkar said he would talk to all parties except Sinn Fein about forming a government. The option of another minority government also remains, with Fine Gael or Fianna Fail backing the other from the opposition benches. Votes were cast on Saturday and counting began on Sunday morning, with the result not being known until Monday or Tuesday.