TOMORROW is Fine Gael and Labour's 750th day in office, and it also brings the Coalition's first big electoral test.
Both parties – particularly, but not exclusively, Labour – have reason to be distinctly nervous about the by-election in Meath East.
By-elections are normally hopelessly unreliable indicators of the national picture. Successive governments here went 30 years without winning one before Labour – still in the afterglow of the Coalition's thumping general election victory – won in Dublin West in October 2011.
More than a decade ago, in the space of a year, Fianna Fail was humiliated in two by-elections in Tipperary South, prompting predictions of general election disaster. Eleven months after the second loss, the party came within a few hundred votes of an overall majority in the 2002 general election. Fine Gael, which won the first Tipp South by-election handsomely, was almost wiped out.
Voters tend to use by-elections as a chance to have a swipe at the Government, even in good times. Local factors tend to dominate. And, much more than in general elections, the electorate appear to favour the candidate who they see as being "due a go". But Meath East may prove to be a better yardstick than normal.
The circumstances that caused the by-election – the death of popular junior minister Shane McEntee – have surely negated the usual disadvantage facing governments in by-elections, at least for Fine Gael.
Shane's daughter, Helen, is hoping to win the seat her father first won in another by-election in 2005. She is an impressive candidate and has been keen to stress that voters should look beyond her name to see what she can offer as a TD.
That said, there is no question that there will be an enormous sympathy factor at play. The McEntee name also carries weight in Meath, particularly in GAA circles.
If Fine Gael fails to hold the seat in such circumstances, it would be a huge upset and a measure of how the party's stock has fallen with voters. Defeat at the hands of Fianna Fail would make it particularly unpalatable. After nearly 80 years of playing second fiddle to Fianna Fail before trouncing it in the general election of February 2011, Fine Gael would hope to maintain top-dog status for longer than this.
However, the indications are that Fine Gael will do enough to hold the seat. Party insiders are cautiously optimistic that Helen McEntee will top the poll. Even if she doesn't, they believe her ability to attract transfers will see her home. However, with turnout likely to be very low, nobody in Fine Gael will be relaxing at least until the first tallies are in on Thursday morning.
In contrast, the Labour leadership already knows it is staring into an abyss. The party won a seat here two years ago with Dominic Hannigan topping the poll with 21pc. But the word is that its by-election candidate, Eoin Holmes, will struggle tomorrow to land much more than a third of that support level.
In the circumstances, government voters were always going to plump for Ms McEntee ahead of Mr Holmes, but if the party comes in under 10pc in a constituency where it should be strong, it will be a significant blow. It will also increase the pressure on Eamon Gilmore.
UP to now, discontent with Mr Gilmore's leadership and with Labour's poor opinion poll ratings has been confined to private grumblings in sections of the parliamentary party. It should – and probably would – take more than a by-election humbling to cause more open and widespread revolt (next year's local elections, perhaps?).
But some of the new Labour TDs have shown a worrying tendency to over-react in recent months, so nothing can be ruled out.
And it's virtually inevitable that a Labour collapse in Meath East will impact on relations in the Coalition. The Labour leadership will come under pressure to flex the party's muscles in government and show some 'wins'. That's never a good thing for the stability of a coalition.
So whatever happens tomorrow it's hard to see any upside for the Coalition. Even if Fine Gael wins the election war, it could end up losing the peace in its government.
Shane Coleman is Political Editor of Newstalk 106-108FM.