Ireland’s political leaders have been left red-faced in Brussels before, when voters rejected major European treaties.
Such was the upset after the initial Lisbon and Nice Treaty referendums, that the Irish people were effectively sent back to the polls to get it right.
However, the Fine Gael/Labour coalition has insisted there will be no re-run this time around.
They have argued the fiscal compact only needs 12 countries on board to ratify it.
Nonetheless, all eyes in Europe will remain fixed on Ireland.
As the only member state putting the controversial deal to a popular vote, Ireland is the only official barometer of public opinion.
Observers believe turnout could be a key factor in the result.
When the Irish electorate first refused to support the Nice Treaty in a referendum in June 2001, just 35% of voters turned out. The treaty was rejected.
But on the second time of asking, the following year in October 2002, the deal was passed with a bigger turnout of almost 50%.
When the Lisbon Treaty was first put to Ireland in the summer of 2008, it was also rejected, on a turnout of 53% of eligible voters.
But again, on the second time of asking just over a year later, it was passed. On that occasion, there was a swell in the electorate turning out, up to 59%.
In the interim, the Government had claimed it secured guarantees on contentious issues including corporation tax rates, neutrality and abortion.
Ireland’s Constitution requires it to hold a referendum on major issues.
The vote on the fiscal compact was called following legal advice from Attorney General Maire Whelan.
The Government refused to disclose the reasons, with Taoiseach Enda Kenny only saying the advice was that “on balance” a referendum was required to ratify it.