The sprawling and largely rural constituency of Fermanagh and South Tyrone is the largest of the 18 in Northern Ireland, and has the longest border with the Irish Republic.
It is also the most closely contested of all 650 Westminster seats, with Sinn Fein’s Michelle Gildernew (21,304) having previously won by a mere four votes against the agreed unionist figure of Rodney Connor (21,300).
During 2010, the turnout was 69.3 per cent.
This time around, Tom Elliott of the UUP is running with the support of the other unionist parties in an effort to unseat the republican incumbent who does not take her seat in the House of Commons.
Although the constituency has a Catholic/nationalist majority (57 per cent), the SDLP’s share of the nationalist vote could open the door for a unionist to top the poll. However, in 2010 that SDLP share of the green vote was small.
Ulster Unionist Ken Maginnis had held the seat for 18 years, having defeated Owen Carron of Sinn Fein in 1983.
However, the seat was re-taken by Michelle Gildernew in 2001.
No pact between Sinn Fein and the SDLP has been agreed, but Mrs Gildernew has suggested in recent weeks that a sizeable number of SDLP voters could vote tactically for her party rather than allow the unionist initiative to succeed.
Tom Elliott has accused Sinn Fein of running a negative campaign. He said he would take his seat at Westminster to represent the entire constituency – particularly on issues of great concern to the mainly rural community.
“Sinn Fein are running a very negative campaign, calling me an agreed Orange/Tory candidate,” he said.
“I’m assuming that’s because they don’t have anything positive to offer.
“If you go to Westminster at all, you’re obviously going to represent people better than an abstentionist.
“I would be confident that I can attract votes from both sides of the community.
“Among the farming community, CAP reform is a massive issue.
“Westminster decides where the distribution [of subsidies] goes and there is a planned review for 2017.
“If Northern Ireland was to lose some of its CAP reform monies that would be pretty major for them.
“You get the local issues as well such as health and education and also welfare reform.”
In a recent newspaper interview, Mrs Gildernew hinted that an end to Sinn Fein’s abstentionist policy could not be ruled out in the long term, but said it was unlikely to happen any time soon.
“Well, I never say never but the time and circumstances are not right now and to be honest I don’t feel that the British have any need to involve themselves in Irish politics so why would I feel the need to involve myself in British politics,” she had told the Fermanagh Herald.
Mrs Gildernew first won the seat she has held for 14 years by 53 votes in the 2001 election.
The poll was marred by an incident at a polling station in the border village of Garrison, where Sinn Fein supporters kept the venue open beyond the 10pm deadline.
A judgement reviewing the incident found that “scenes of threatening intimidation” had taken place, but that the incident was not serious enough to change the outcome.
But even that narrow margin looked relatively comfortable compared to the last Westminster poll.
Her four-vote majority was arrived at by a series of recounts, and was ultimately reduced to just one vote by a later review by the electoral courts (although the Electoral Office for Northern Ireland still lists her as having a four-vote majority).
Echoing Tom Elliott, the former Sinn Fein agriculture minister at Stormont said she believes she can pick up votes from those on the other side of the traditional political divide.
“We can’t assume that everybody who votes for me would vote for a united Ireland,” she said.
“I have a friend who is very great with a young Orangeman in Fermanagh, and he told my friend that ‘my family didn’t vote for Michelle but we know lots of people who did’ - so that’s the kind of thing you hear back...
“Fermanagh and South Tyrone is going to still be talked about as one of the most divided and polarised communities, but it is not.
“People vote on the basis of thinking through what they need to do for the future of their families.”
Candidate for the SDLP John Coyle dismissed any suggestion his vote will be squeezed in what most commentators predict will only ever be a two-way fight.
Mr Coyle said: “Nobody has the right to say that it is their seat. A seat can be won by anybody. You have to be the best candidate overall and I believe I am the best candidate and it isn’t a two horse race.”
COYLE, John (SDLP)
ELLIOTT, Tom (UUP)
GILDERNEW, Michelle (Sinn Fein)
JONES, Tanya (Green Party)
SU, Hannah (Alliance)
Michelle Gildernew (Sinn Fein): 21,304
45.5%, up by 7.3% on 2005
Rodney Connor (an independent unionist, agreed by both the UUP and DUP): 21,300
Fearghal McKinney (SDLP): 3,574
7.6%, down 7.2%
V Kamble (Alliance): 437
John Stevenson (Ind): 188
Michelle Gildernew (Sinn Fein): 18,638
Arlene Foster (DUP): 14,056
Tom Elliott (UUP): 8,869
Tommy Gallagher (SDLP): 7,230
Michelle Gildernew (Sinn Fein): 17,739
James Cooper (UUP): 17,686
Tommy Gallagher (SDLP): 9,706
Jim Dixon (an independent who recieved support from the DUP): 6,843