Support for Sinn Fein, the former political wing of the Irish Republican Army, surged in Ireland’s national elections on Saturday, according to exit polls. Prime Minister Leo Varadkar’s party, in power since 2011, was weakened but the result left open the possibility that he could still hold onto his office.

If the exit polls prove accurate, the vote boiled down to a three-way tie in a three-way race between Sinn Fein, Mr. Varadkar’s Fine Gael party and the leading opposition party, Fianna Fail. This would give Sinn Fein a shot at joining the next coalition government.

A joint exit poll commissioned by The Irish Times and state broadcaster RTE showed Fine Gael at 22.4 percent, Sinn Fein at 22.3 percent and Fianna Fail at 22.2 percent.

Analysts said the center-left Sinn Fein was boosted by younger and urban voters angered by austerity policies implemented by successive Fianna Fail and Fine Gael governments following the 2008 financial crash. It capitalized on frustrations over housing and health care crises largely blamed on Mr. Varadkar’s party.