The Northern Ireland Assembly election in Fermanagh-South Tyrone features two of the DUP's and Sinn Féin's most popular women politicians – First Minister Arlene Foster and Michelle Gildernew.

Yet, for a while it appeared that Sinn Féin was intent on bumping Ms Gildernew off the ballot paper. First, she was selected at a party convention to run with two other Sinn Féin candidates, MLA Seán Lynch and Fermanagh councillor John Feely.

Outgoing Sinn Féin MLA Phil Flanagan failed to get the nomination. But then headquarters decided there was a procedural problem with this convention and ran a second one – in which Messrs Lynch, Feely and Flanagan were selected, but Ms Gildernew surprisingly was jettisoned.

There was some speculation that this was HQ punishing Ms Gildernew for narrowly losing her House of Commons seat to the Ulster Unionist's Tom Elliott in the 2015 Westminster election.

But no, it wasn't a conspiracy, it was a cock-up. This was established by the fact that Sinn Féin decided to hold a third convention, this time restricted to the South Tyrone part of the constituency which – surprise all round – put Dungannon woman Ms Gildernew back on the ticket.

But it meant, in a tightly contested battle, Sinn Féin now had four candidates seeking to hold on to its three seats when it appeared to make more sense to just run three. Sinn Féin is noted for how disciplined it is in organising vote transfers down the line, but with four candidates plans can go awry.

Now Sinn Féin could confound everybody and win four seats, but there is a possibility too that the conventions debacle could open the door for the SDLP to regain the seat it lost in the 2011 Assembly contest.

Five years ago, again with Ms Gildernew fronting for Sinn Féin, the party gained a third seat by squeezing out – by a couple of hundred votes – the veteran SDLP stalwart and longstanding MLA Tommy Gallagher.

This time Richie McPhillips, a local councillor from Newtownbutler, Co Fermanagh is running for the SDLP. In the 2014 local government election he won just over 1,000 votes. He would need a stronger vote base than that to get elected, but, equally, if the SDLP vote turns out for him throughout the constituency then Mr McPhillips has a good chance.

The SDLP fared poorly in last year's Westminster election, but that was no surprise because in essence that was an Orange versus Green sectarian headcount battle between Ms Gildernew and Tom Elliott. If, however, the SDLP can replicate its good performance in the 2014 local government election, then it could be back in Stormont.

In the outgoing Assembly, Sinn Féin held three seats, the DUP two, and the UUP one. But if the UUP could measure up to the performance of Mr Elliott in defeating Ms Gildernew in the Westminster election then it could gain a seat at the expense of the DUP. This is a constituency UUP leader Mike Nesbitt has in his sights. Still, it must be remembered that the DUP stood aside in that contest.

Nonetheless, in the local elections two years ago the UUP out-performed the DUP and on such a repeated showing could steal a seat from the DUP.

Prediction

The popularity and vote-winning capability of Ms Gildernew and Ms Foster could be critical in determining the result of this election. Ms Gildernew will do well, but having four rather than three candidates could undermine Sinn Fein’s prospects of holding its three seats.

Ms Foster, since being elevated to the posts of DUP leader and First Minister, has grown in stature and profile. The DUP, which has just two candidates, will be depending on her newly raised status and popularity to see off the challenge from the UUP and return her and the DUP chairman Lord (Maurice) Morrow to Stormont.

It will be fiercely contested but when the votes are counted it could result in:

DUP (2); Sinn Féin (2); UUP (1); SDLP (1).

Candidates

Rosemary Barton (UUP)

Kerri Blyberg (Alliance)

Donald Crawford (TUV)

John Feely (Sinn Féin)

Phil Flanagan (Sinn Féin)

Arlene Foster (DUP)

Michelle Gildernew (Sinn Féin)

Damien Harris (Lab Rep)

Tanya Jones (Greens)

Seán Lynch (Sinn Féin)

Richie McPhillips (SDLP)

Maurice Morrow (DUP)

Alastair Patterson (UUP)