Fermanagh and South Tyrone—which, in its present form, has remained much the same since 1950—is a genuinely fascinating constituency. It was and continues to be the most electorally polarised constituency in Northern Ireland; which also explains why it usually has the largest turnouts, the tightest margins of victory and what might be described as a regularity of changeovers between the two community electoral blocs. Indeed, in the twenty-three general elections and by-elections since 1950, unionists have won ten of them and nationalists thirteen. And that’s what makes it so difficult to call the result beforehand.

A sign of the closeness of these contests can be gauged by the fact that in only two of the elections since 1997 has the winning majority been greater than 1000 votes. Sinn Fein, for example, held the seat in 2019 with a majority of just 57. Mind you, that seems enormous when contrasted with its majority of 4 in 2010! Yet even with such a slim majority in 2019 Sinn Fein felt comfortable enough to switch Mitchelle Gildernew to the Euro elections in what it thought was a fairly safe seat in the Midlands-North-West constituency.

It's always risky to move a big hitter in a constituency with notoriously tight margins. Recent boundary changes saw some tinkering around the edges, with some gain from Newry and Armagh and some loss to Mid-Ulster. I won’t bore you with the minute details, but the view of the numbers experts is that the changes may be (and that’s a very big ‘may’ of course) to Sinn Fein’s advantage--in the region of around 500 votes. So again, those figures suggest that the July 4 contest will likely be remarkably close.

Sinn Fein’s decision to field Pat Cullen came as quite a surprise and was regarded in some quarters as something of a coup for the party. She came with an established and significant profile, always an advantage for a new and untested election candidate. But she was also dogged by controversy in terms of her nursing background and the fact that nurses and hospital staff in general had to deal with the aftermath of IRA bombing and shooting incidents.

But when you join a political party—any political party as it happens—you take on the history and baggage of that party. Pat Cullen will have known the questions she would be asked. She would almost certainly have been briefed on a range of answers or non-answers. She will be aware of the reaction to her decision, particularly from the unionist community. But here’s the thing: Sinn Fein doesn’t and never really has been overly concerned with what unionists think (and the feeling, in general, is reciprocated). She has agreed to be their candidate—history and baggage included—and for the purposes of this election that is all that matters.

Diana Armstrong, daughter of former UUP leader Harry West (he was also the MP for a few months in 1974) is the unionist candidate. She has been a councillor since 2016 and was selected by the UUP at the end of January, when the general expectation was that there wouldn’t be an election until late autumn. It wasn’t until the end of May that she was confirmed as the sole unionist representative, because both the DUP and TUV seemed keener on a single agreed candidate, as had been the case in 2010, when Rodney Connor lost by four votes.

But a July election, called on May 22, cut back the time for negotiations and on May 28 the Fermanagh and South Tyrone UUP Association confirmed Armstrong as its choice. The following day the DUP agreed not to field a candidate, ‘for this election only,’ and the TUV followed suit. She remains a UUP candidate, rather than an agreed candidate, but it would be surprising if the unionist electorate didn’t rally to her.

For all of the talk about unionist pacts in this constituency Rodney Connor was the first officially ratified ‘agreed’ candidate and also the first time that the UUP hadn’t been the lead unionist runner. In eighteen of the twenty-three elections since 1950 the UUP fielded the only unionist candidate. In 1964 an Ulster Liberal also stood; in February 1974 (the Sunningdale era) a pro-Assembly unionist stood and was defeated by Harry West; in 1979 the UUUP fielded Ernest Baird (had he not stood the UUP would probably have beaten Frank Maguire); in 2001 the anti GFA and Poppy Day bomb survivor William Dixon stood as an independent (had his 6,843 votes been added to James Cooper’s 17,686 then Michelle Gildernew would have lost); and in 2005 she won again when both Tom Elliott and Arlene Foster stood and divided the vote.

The lesson from this—and it can be traced back to 1979—is that when two unionists stand, particularly when they both poll fairly well, there is very little chance of winning. And it’s also worth noting that a number of unionist successes, particularly during the Ken Maginnis era (1983-2001), were probably due to one unionist versus SF/SDLP and some fringe nationalists. Sinn Fein has also benefitted from a severe reduction in the SDLP vote over the past twenty-five years as the contests became, to all intents and purposes, a battle between Sinn Fein and a single unionist.

This, of course, makes life difficult for the smaller parties, especially the SDLP and Alliance. In 2019 they won about 12% between them, while in the three elections before that their joint tally was about 7%. I don’t expect Paul Blake (SDLP) or Eddie Roof (Alliance) to go much above a joint tally of 10% or so this time, not least because this is even more of a grudge battle than 2019. The UUP wants to win a seat it last won with Tom Elliott in 2015 and unionism generally seems to have more trouble with Pat Cullen as a candidate than might have been anticipated by Sinn Fein.

And with the greatest respect to Labour Alternative candidate Gerry Cullen and Aontú candidate Carl Duffy (I have a lot of respect for candidates who stand in seats where their chances of success are zero) I don’t expect them to burden the counters at the count centre on July 4. What might be worth looking out for, albeit mostly with the SDLP and Alliance, is whether their vote slips in favour of Sinn Fein or the UUP. As I keep saying, when you’re in tight margin territory then a handful of votes here and there can be the difference between winning and losing. I’m not going to hazard a guess about whether Cullen or Armstrong will carry the day, but I do expect it to be close.