It is an article of Irish republican faith not to acknowledge the authority of the British crown. So the fact that Gerry Adams, of all people, did it symbolically this week is important, because symbols matter to republicans. By submitting to the procedural charade – which should be replaced – of accepting a meaningless medieval office in order to resign his Westminster seat, the Sinn Féin leader showed how desperate he is to take part in the most important Irish general election in decades.

This year's Irish election will be an all‑change affair, but not just for Adams, who is trying to win a seat in Louth. The exact election date – late February or early March – will be announced in the next few days. Often, Irish elections tend to be of local interest only. The British, ignorant and condescending where Ireland is concerned, rarely devote a fraction of the interest to Irish contests that they lavish on far less relevant US ones. But this 2011 election ought to be an absolute cracker.

There are two main reasons for this. The imminent collapse of Brian Cowen's government will provide Europe with its first general election directly triggered by the tumult in the eurozone. So it will be nervously watched by governments in every capital across the continent – David Cameron is certainly doing so in this country. But it also looks set to be a milestone in Ireland's history, perhaps marking the historic downfall of Eamon de Valera's Fianna Fáil party, the political movement that has done more to shape the 90-year history of our independent neighbour than any other.

In one sense, it is a surprise that Ireland should be going to the polls now. Why call an election when the polls say that you will lose and when parliament has more than 12 months to run? The government coalition had a working majority for its controversial economic policy until it fell apart a few days ago. The austerity package imposed as a result of November's €85bn EU bailout is about to go through, even so. Adrift in the polls, Cowen and his coalition would try to hang on to power in any normal circumstances.

But these are not normal circumstances. Ireland's exposure to the banking collapse of 2008 and the bond market challenge of 2010 were an economic double-whammy compounded by the country's increasingly old-fashioned party politics. Unlike in Greece, where the single-party socialist government managed to hold on to power last spring in spite of the economic shock of the bond market battering, Ireland's Fianna Fáil-Green coalition has imploded under the weight of unpopularity. That says something about brittle coalitions in conditions of crisis – UK observers take note. Even more, it says something specific about Irish party politics, which are still framed by the events of 1921 and which, especially in Fianna Fáil's case, have become recklessly complacent.

As soon as the autumn bond market crisis broke in Dublin, Fianna Fáil and the Greens turned against each other. Then, in the new year, Fianna Fáil increasingly turned in on itself, with Cowen winning a pyrrhic victory over a challenge from Micheál Martin last week, only to resign the party leadership at the weekend and be succeeded by Martin on Wednesday. It may not be as spectacular as the uprisings taking place in the Arab world. But it is a revolution of a kind, all the same.

Opinion polls show the centre-right Fine Gael and the centre-left Labour party are on course to be the big winners when the vote comes, probably for no better reason than that they are the opposition. Fianna Fáil is struggling to stay in third place against the challenge of Sinn Féin, while the rest, including the battered Greens, trail far behind. The likelihood of Fine Gael's Enda Kenny taking over as prime minister from Cowen at the head of an FG-Labour coalition is widely assumed, not least in London. Cameron and Kenny had a long telephone conversation on Sunday.

Ireland is used to changes of government of that kind. There have been several FG-Labour coalition governments in the past, most recently in the 1990s. What would be unprecedented, however, would be for Fianna Fáil to slump to something like the 14% recorded in a Red C poll this month. For a party that has not slipped below 39% in any general election since it first took power under De Valera in 1932, such a result would be nothing short of catastrophic. Even Martin is only talking of getting into the mid-20s, which in any other circumstances would be humiliating.

But what would be the longer-term consequences? It is tempting to say a humbling would genuinely mark the end of the Fianna Fáil era. A party that was successively the carrier of De Valera's austere Celtic exceptionalism, of Charlie Haughey's Tammany republicanism and of Bertie Ahern's good-time wheels and deals – all of which belong to the past rather than the future – is a party that has perhaps now completed its historic nationalist mission. Surely, as the Irish Independent columnist Martina Devlin argued today, Fianna Fáil would now be better off merging into a European-style centre-right block with Fine Gael.

The problem, though, is that Ireland cannot escape its exceptionalism quite so easily. It is not a nation like others because no nation is quite like another. Even if an Ireland based on European-style centre-left versus centre-right politics may seem generally more suited to the 21st century than a politics based on the position your great-grandparents took to the Anglo-Irish treaty, those left-right politics are themselves dissolving and fragmenting and are now also adjusting to the impact of the financial crisis.

In Ireland, as elsewhere, voters are keen to penalise the governments that led them into financial crisis and the bank bailouts. But voters don't like the austerity imposed by their replacements much more either. If that process takes place in Ireland, then, yes, Fianna Fáil will lose badly in a few weeks time. But then, rather like the Tories have done here, Fianna Fáil may recover and reinvent itself, not disappear into the mists of history.

Old politics can be inconveniently tenacious in any country. We British ought to know this. The large bomb scare in north Belfast today is a reminder of one aspect of that in the Irish context. It would be foolish to write off Fianna Fáil too, however much of a drubbing it gets. It may not be so long before it returns, perhaps even in coalition with Sinn Féin, just in time for the centenary of the Easter Rising in 2016, or for that of the treaty five years later.