DUBLIN (Reuters) - Irish nationalists Sinn Fein surged ahead of the governing Fine Gael party to draw level at the top of an opinion poll a week before an election that looks set to be a major breakthrough for the former political wing of the Irish Republican Army.

FILE PHOTO: Sinn Fein Leader Mary Lou McDonald in Brussels, Belgium April 1, 2019. REUTERS/Francois Lenoir/File Photo

The Business Post/Red C poll put the left-wing Sinn Fein up five percentage points in the space of a week to 24% and level with the center-right Fianna Fail, which fell two points. Support for Fine Gael dipped by the same amount to 21%.

Sinn Fein stood at 11% in the last Business Post/Red C poll before Prime Minister Leo Varadkar called the Feb. 8 election that has focused on the high cost of housing and deficiencies in healthcare in the European Union’s fastest growing economy.

Setting out her party’s priorities in Dublin on Sunday, Sinn Fein leader Mary Lou McDonald said voters had an opportunity to disrupt the political balance that has seen Fianna Fail and Fine Gael swap power since the foundation of the state.

“Fianna Fail and Fine Gael have been in power in this state for almost a century. They’ve had it all their own way and they’ve had their chance,” she said.

Running fewer candidates than it did in the 2016 election and around half the number being fielded by both Fine Gael and Fianna Fail, all 42 Sinn Fein candidates would likely have to be elected to the 160-seat chamber to give it a shot at emerging as the largest party.

Such a scenario remains highly improbable, analysts say.

However a marked improvement on its 22 outgoing seats would put pressure on the two traditionally dominant parties to drop their refusal to govern with Sinn Fein, both due to the party’s IRA links and its opposing economic policies.

Speaking on BBC’s Andrew Marr Show on Sunday, Leo Varadkar said “you won’t see a coalition between my party and Sinn Fein, that’s not going to happen”.

“The likelihood is it’s actually going to be very difficult to form a government over the next couple of months.”

The other option is a second successive minority government, this time more likely led by Fianna Fail but needing another “confidence and supply” deal with Fine Gael.

The two historic rivals have never gone into coalition government together and Fianna Fail still resists such a move.

All other opinion polls so far during the campaign have put Fianna Fail in front on its own, with most showing Sinn Fein closing in on Fine Gael in second place.

“The crucial campaign momentum is with Sinn Fein, and appears founded on a desire for fundamental change in the established order,” said Red C chief executive Richard Colwell.

“What is apparent is that, on these numbers, it is going to be difficult for any party to form a government unless they go into coalition with each other. The alternative is that we could be having another election very soon.”