sinn fein varadkar macdonald
Make no mistake, this poll is seismic. And if replicated on this day next week, it would represent Sinn Féin's greatest breakthrough in over a century.

Mary Lou McDonald and her party are heading for government, and soon, if not this time around.

It was on December 14, 1918, that old Sinn Féin swept the board across Ireland and consigned the Irish Parliamentary Party to oblivion. That was, ironically, the last time a general election was held on a Saturday in Ireland.

The poll, carried out by Panelbase for The Times, puts Sinn Féin in second place on 21 per cent support; the very stuff of Republican dreams. It emulates a previous 21 per cent rating found by an Irish Times poll last month.

But sweeter still is consigning their bitter enemies in Fine Gael to an embarrassing third place, meaning that the Sinn Féin day — always coming, according to their Irish-language slogan — has more or less arrived.

sinn fein 1918 election result
It is no less a breakthrough for Ms McDonald and her "clean-hands" comrades than the post-1916 sampling of national sentiment a century ago.

There are a number of rather large caveats that must be taken into account. Online polling is the norm in the UK, but it is new to Ireland and this is the first opinion sample of its kind. Also, the gap between Fine Gael and Sinn Féin is within the 3 per cent margin of error, meaning the Republican party could easily finish in third place when the votes are counted next week.

Sinn Féin also has a habit of polling higher than its eventual result, a trend that was seen in the 2016 general election when the party received just under 14 per cent of the vote, despite polling between 16 and 21 per cent at different times throughout the year.

But if the poll proves accurate then Sinn Féin will have stolen support from the two big parties, whose support is down from late last year as measured by other polls. Its 21 per cent, to 23 per cent support for Fianna Fáil and just 19 per cent for Fine Gael, demonstrates that it is poised to become the lead party of a left-wing government in the very near future.

For the two big traditional parties to come together in a so-called "grand coalition" in post-vote negotiations on government formation will only further play into Sinn Féin hands. Theirs has always been a long game.

And it is a long time since their Long War. The first IRA ceasefire was in 1994, before being formally re-established again three years later.

A generation has passed. Sharing power in the North has been set against prolonged political quarantine in the South for perceived past misdeeds.

Again, if replicated on polling day, the seizure of the second-highest share of the first preference vote in the Republic would represent the people telling the politicians that the period of de-lousing is over. And that's despite Sinn Féin having in its outgoing political ranks a man wanted in Britain on 50 counts of alleged murder.

Ms McDonald, 50, seems to have won over many women, her no-nonsense scolding of the senior men in the "conservative parties" seeming to have touched a distinct chord.

Her pitch is also playing with frustrated young commuters and the stretched city renters of the middle class. Many of Mr Varadkar's early risers seem to have gone over to the party of simply the Rising, that outbreak having been labelled the "Sinn Féin rebellion" in the British press of the time.

This, however, has all the hallmarks of a bloodless revolution, consisting of persuading voters who see themselves as missing out that it is the very definition of folly to vote for either of the big two that dominated the last century here, while expecting anything to significantly change.

The other salient feature of this poll is that it guarantees a hung Dáil. In 2016 it took months to put together a ruling arrangement though confidence and supply, and that was before the British referendum on Europe. There are obvious perils now.

The Greens will form a significant seat bloc on 10 per cent, with Labour half their size at 5 per cent, less than a quarter of Sinn Fein support.

Our sample results also show the Social Democrats and Solidarity/People Before Profit each on 5 per cent, unusually high in comparison with polls over the last year, but possibly reflecting Róisín Shortall and Richard Boyd Barrett's able performances in the first seven-way debate, which fell within the week-long polling timeframe to Thursday of this week.

Those questioned were balanced statistically for age, gender, geographical distribution and income. But the overall results exclude don't knows, and the findings indicate that only 59 per cent of voters are unshakeable in their intentions. Fully 41 per cent concede they may change their minds when the pencil hovers over the paper.

One in eight (13 per cent) of those likely or very likely to vote say they are currently undecided, but it is traditionally on the last weekend of a campaign, i.e. this weekend, that many make up their minds.

In the past, the main political parties haughtily discounted one third of Sinn Féin's poll numbers, understanding that many of those asked their opinion knew that a claimed radical allegiance would upset the establishment, while others were too apathetic or beset by problems to get to the polls. That looks a distinctly forlorn hope this time around.

Sinn Féin is about to go mainstream.