PRESIDENTIAL elections – they don't come around too often. The opportunity for an election arrives, at best, just once every seven years. But as often as not, the opportunity to hold an election has been passed up by the political establishment.

In the almost three-quarters of a century since the office of presidency was created, there have been only six elections – a strike rate of just one every 12 years – with six uncontested inaugurations.

For the political anoraks out there, the occasions when a presidential contest happened in the same year as a general election are even more rare. It has happened only before (in 1973, when Erskine Childers beat Tom O'Higgins, and 14 years ago, when Mary McAleese easily emerged from an unprecedented field of five candidates to take the presidency).

And of course this year is poised to be the third time – or is it? With President McAleese's term ending in the autumn and several candidates already expressing interest, it has long been assumed there will be a contest in 2011. But the March general election could change all that.

By far the most likely outcome of that election is a Fine Gael-Labour coalition and a severely chastened Fianna Fáil on the opposition benches. The prospect of a presidential election in October is unlikely to appeal to any of the three main parties. Fine Gael and Labour, still presumably in their honeymoon phase, may not relish the idea of the two parties going head to head in a costly and potentially divisive contest. And will the new leader of Fianna Fáil, just starting out on a rebuilding phase and seriously short of money, want to fight an election the party has little chance of winning?

The potential for the three main parties to come up with an agreed candidate, as happened in the past with Paddy Hillery, Cearbhall Ó Dálaigh and Douglas Hyde, cannot be ruled out.

David Norris, who has already formally declared his presidential ambitions, might have something to say about that. Norris would need the nomination of either 20 Oireachtas members or four county councils to get into the contest. If the main parties were opposed to it, the latter option would be closed off but, with the prospect of a host of independents being elected to the next Dáil, the potential to secure the backing of 20 TDs and senators cannot be ruled out.

"We reckon Norris could get around 17 names at the moment but the new Dáil could throw up a more benign scenario for him. And if he gets the 20 names then the die is cast and there will be a contest," said one senior opposition politician. But he acknowledged that if that scenario didn't arise, the potential arose for the three main parties to come up with an agreed candidate without any political affiliations.

The senior deputy put the chances of a presidential election at around 70-30, but those odds could shift depending on the number of independents or Sinn Féin TDs elected in March.

And while it is possible that the main parties will not want a contest, there could be reasons they do. Enda Kenny shrewdly declared, well in advance of the end of Mary McAleese's first term, that Fine Gael would not be contesting any 2004 presidential election. He knew she couldn't be beaten and, with Fine Gael in need of rebuilding, had bigger fish to fry. But flush from an election victory in which Fine Gael finally overtook Fianna Fáil, he might be tempted to reinforce his party's supremacy by laying to rest Fine Gael's disastrous record of never winning a presidential election.

While Fine Gael would still love to see John Bruton go forward, Mairéad McGuinness looks the most likely Fine Gael candidate, although fellow MEP Seán Kelly cannot be ruled out.

Labour, meanwhile, already has two senior figures who have declared their intention to contest the presidency: former minister Michael D Higgins and Barnados chief executive Fergus Finlay. Speaking to the Sunday Tribune last week, Finlay said a move to avoid a presidential contest would be "wrong, divisive and unlikely to succeed", adding that he was "strongly of the view that the unique nature of the office" came from the fact that it was the only one directly elected by the people. The office had been "diminished in the past by long periods between elections and it would be entirely wrong to do so [in 2011]", Finlay said.

Michael D Higgins, who has opted not to contest the upcoming general election, is perceived in political circles as the favourite to win the Labour nomination. And there is a view that he would "need some amount of convincing" to stand aside for an agreed candidate if the new coalition wanted him to.

By the end of the summer, Fianna Fáil may also see advantages in contesting a presidential election. The new government may already have lost some of its sheen with the electorate by then and the prospect of the coalition partners going head to head could be tempting.

Brian Crowley is the most likely Fianna Fáil candidate in any contest (forget speculation about Bertie Ahern – it's not going to happen).

And while the perception is that Crowley would be highly unlikely to win, given these troubled times for the party, he would probably perform very credibly and such a performance could give a morale boost to the entire organisation.

Assuming he gets the nomination, there are mixed views around Leinster House about Norris's prospects. One senior Fianna Fáil minister told the Sunday Tribune that the Trinity senator had already generated considerable momentum and would take a lot of stopping. However, a senior Fine Gael source argued that his campaign would "run out of steam" in the long run-up to an October polling date.

The same, of course, could yet hold true for the entire political establishment. Between now and March, the general election will be the only game in town, and given the likely seismic impact of that election, don't rule out the prospect of the presidency staying pretty low on parties' priority lists afterwards. The odds may be 70-30 in favour of a contest now, but history tells us the odds are seldom better than 50-50. Why should 2011 be any different?

Who will be the next president?

Paddy Power Odds

Michael D Higgins 5/2

Brian Crowley 10/3

David Norris 7/2

Fergus Finlay 4/1

John Bruton 11/1

Seán Kelly 11/1

Mairéad McGuinness 16/1

Mary Davis 20/1

Bertie Ahern 22/1

John Hume 25/1

Emily O'Reilly 25/1

Mary O'Rourke 25/1

Séamus Heaney 33/1

Mary White (FF) 33/1

Gerry Adams 40/1