Connor poses a long-term risk for nationalism

The agreement by the DUP and UCUNF to withdraw their candidates in Fermanagh and South Tyrone in favour of a 'unionist unity' candidate poses long-term challenges for nationalists in the constituency.

Unionists in the constituency, despite having proved that David Cameron is a liar, will be ecstatic about the outcome, which is an almost certain win for them. The Tories, despite having to mumble half-excuses about how "Fermanagh and South Tyrone has characteristics that are unique within the UK" will, at the end of the day, probably have another vote to count on in Westminster – and that is all they really care about. The DUP have eaten the most humble pie, though. Despite being the largest unionist party in the constituency in recent elections, they have had to stand aside for a man who will lend his support to their opponents. Whether the 'recapture' of the seat for unionism as a result of their pressure for a pact will adequately compensate them, we may have to wait another year to see.

The 'unionist unity' candidate, Rodney Connor, is himself part of the problem for nationalism. He is apparently a decent man and quite well thought of by nationalists in the area. How strong his unionism is, is open to question – the unionist parties think that he is 'one of theirs', but he has joined neither party, and insists that he will act in the interests of the whole constituency. Given that that constituency is majority nationalist, it will be interesting to see how he does that.

But potentially more damaging for nationalism will be the loss of the constituency. History shows us that when the seat is held by a nationalist – especially a 'nationalist unity' individual like Frank Maguire (MP from 1974-1981) – the nationalist vote is high, but when a unionist wins the seat – usually as a result of a split nationalist vote – it seems that some nationalists withdraw from voting. After Ken Maginnis won the seat in 1983 thanks to the decision by the SDLP to stand again, the number of nationalist votes tumbled. Maginnis retained the seat thanks to his role as 'unionist unity' candidate in 1986, 1987, 1992 and 1997. In all of these elections both Sinn Féin and the SDLP stood, and nationalists knew that they could not win the seat. The nationalist vote dropped as a significant proportion simply didn't bother to turn out.

Although the constituency lost the heavily nationalist Coalisland area to Mid Ulster in the 1995 boundary revision, and FST became a more evenly split constituency, it remained winnable for nationalism. The result in 2001, when Sinn Féin finally took the seat, thanks to a split in unionism – proved that there were more latent nationalist votes in the constituency than unionist votes. They had just failed to turn out between 1986 and 1997.

And therein lies the problem for nationalism. Faced with a 'unionist unity' candidate and a nationalist split, many voters may again fail to turn out. If Connor wins, subsequent Westminster elections may see the effects of nationalist demoralisation in the constituency, and this could last a decade or more. FST contains a significant number of hard-line republicans who are probably less inclined towards 'constitutional politics' than others, and they are more likely to withdraw from active participation if they feel that it is a waste of time, with a 'unionist unity' victory inevitable.

So Connor has the possibility of not just taking the seat in 2010, but retaining it with increasing majorities for years to come. Only when nationalism senses that it has a good chance of winning, either through a 'nationalist unity' candidate, or a unionist split, will it return to the ballot box in force. The lessons that unionism will draw from the Connor experience are that they must never again split their vote in FST, so nationalism has only three possible hopes in the constituency: either a unity candidate in the short term, or the decimation of one of the nationalist parties, or the slow option of waiting for demography to whittle away the unionist numbers.

The first option – a unity candidate, is not likely in 2010, and barely likely even at the next election. The mutual dislike between Sinn Féin and the SDLP is such that neither would happily give way to the other. The best option in this case would be a 'non-political' unity candidate – someone popular through sport or the media, for example. Fearghal McKinney may have been such a man, but he was seduced by the SDLP's pointless lure.

The second option – the decimation of the SDLP – seemed quite likely in recent years, but the SDLP has made efforts to revive itself, and certainly is not out of the race yet. If it fails badly on May 6, either in terms of votes or seats, its days may be numbered – but that will be too late for FST this time.

The last option - demographics - though slow, is more certain. The graph above shows the number of actual votes received by unionism and nationalism in Westminster elections in FST since 1970. The nationalist number is quite volatile, and includes a decade of demoralised underperformance. The unionist number, however, is less volatile and more consistent. And it is consistently declining – the trend is clearly downward, reflecting Protestant demographics in the constituency. In brief, Protestants are a declining proportion of the constituency's population – from over 50% of the population amongst those aged over 60 (in the 2001 Census) (on the right hand side of the graph), to below 40% of those aged 25 and younger (in the 2001 Census) (on the left hand side of the graph):

So it is likely that demographics will return FST to nationalism in the future, if Connor takes it in 2010. But a quicker and better route would be for nationalism to play unionism at their own game – unity – and beat them.