The terms "unity candidate" and "splitting the vote" make many party activists wince at election time. Both phrases smack of treachery. Westminster's first-past-the-post voting system, a virtually nuance-free process, imposes a tactical crudeness on a political culture not normally known for its genteel side.
Add to this already volatile mix the enmities of West Tyrone on both sides of the already fundamental divide, and you get some idea of the stakes.
West Tyrone was the burial ground for many SDLP hopes at the last general election in 2001. Bríd Rodgers, the former deputy leader, took on Sinn Féin's Pat Doherty in an attempt to wrest the seat from Ulster Unionist hands. She came in a poor third.
The surprise poll-topper in the November 2003 Assembly election came not from any of the established parties. Dr Kieran Deeny, an independent pro-Omagh hospital candidate, scored the largest tally of first preferences with some 15 per cent.
Before polling day some of his backers, notably in the Alliance party, reckoned he was in with a shout for the sixth and final seat. He took the first.
Dr Deeny is now pitching for the Westminster seat, but knows he cannot stand a chance against Mr Doherty unless he gets a clear run from not only the SDLP, but the unionists of all hues as well.
The SDLP, UUP and DUP - as well as Dr Deeny himself - have little in common, except for one thing. They all want to see the back of Mr Doherty and of Sinn Féin, which they blame for a controversial decision to move acute hospital services from Omagh to a new hospital nearer Enniskillen, Co Fermanagh.
Mr Trimble has said he will not withdraw his candidate unilaterally, but will consider not putting up a candidate in the context of a deal with the DUP that it will not contest the seat either. The SDLP, now vociferously rejecting charges from the Deeny camp that it has broken a "gentleman's agreement" to stand aside, has nominated its own candidate.
Eugene McMenamin, an Assembly member, carries the SDLP colours in this election. But the very public row between Deeny and Durkan has, in all probability, damaged both.
Mr Durkan has released tracts of lengthy letters addressed to him by Dr Deeny which he claims disprove Dr Deeny's assertions about pre-electoral arrangements.
Dr Deeny's office has claimed that Durkan's office "is putting personal power and party position before the wishes of the people of West Tyrone."
The hospital campaigner's background suggests he probably has sympathy with the broad SDLP stance. However, some in that party blame him for depriving them of an Assembly seat in November 2003.
There is a strain within unionism that regards Dr Deeny, the SDLP and Sinn Féin as "all coming from the one sow's litter".
At this stage it appears unlikely that any consensus of the sort required to clear the field for Dr Deeny will emerge.
In the meantime, the current MP, Pat Doherty, continues to canvass while dismissing his opponents as being in disarray.