The DUP won ten of Northern Ireland's 18 seats in the 2017 Westminster Election, called by Theresa May.

The party became the key to keeping her minority Conservative Party administration in power.

The DUP's decision to not back the Brexit deal of Boris Johnson - Mrs May's successor - pushed him to trigger next month’s general election.

It is the latest chapter in an ongoing saga of unpredictable twists and turns.

Northern Ireland constituency profile - one
Northern Ireland constituency profile - three

Will Boris Johnson get an overall majority? Might he again be dependent on the DUP in a hung parliament? Could Jeremy Corbyn, helped by the Scottish National Party and/or the Liberal Democrats, become the next prime minister? How will European politics be affected by the first member state divorce in the history of the European Union?

Northern Ireland’s 18 constituencies are providing a juicy quota of subplots. In total 102 candidates are involved.

Voting takes place on Thursday. Counting will begin immediately after polls close at four centres in Belfast, Magherafelt, Omagh and Bangor.

Below is a taster of what's to come.


FERMANAGH AND SOUTH TYRONE 

Outgoing MP: Michelle Gildernew (Sinn Féin) 

Brexit referendum result 2016: Remain 58.6%, Leave 41.4 % 

Sinn Féin candidates for Fermanagh & South Tyrone Jemma Dolan (left), Sean Lynch and Michelle Gildernew

The 2017 story:

Turnout was 76.08%; five candidates contested; with 25,230 votes Sinn Féin's Michelle Gildernew was 875 votes ahead of her nearest challenger, the outgoing MP, Tom Elliott (Ulster Unionist). 

The 2019 contest:

Another Alamo. A border constituency where Bobby Sands was elected a Sinn Féin MP almost 30 years ago. 

Tom Elliott of the UUP is trying to regain the seat he lost to Sinn Féin’s Michelle Gildernew. 

The DUP again standing aside and not putting up a candidate in Arlene Foster’s home constituency. 2017 turnout was the highest in Northern Ireland.

Michelle Gildernew had a four vote advantage over the agreed unionist candidate in 2010. 

Candidates: Matthew Beaumont, Alliance; Tom Elliott, UUP; Adam Gannon, SDLP; Michelle Gildernew, Sinn Féin; Caroline Wheeler, Independent.


WEST TYRONE 

Outgoing MP: Órfhlaith Begley (Sinn Féin) 

Brexit referendum result 2016: Remain 66.8% Leave 33.2% 

Newly-elected Sinn Fein MP Órfhlaith Begley delivering her victory speech in Omagh

The 2017 story: 

Turnout was 68.23 %; seven candidates contested; with 22,060 votes Sinn Féin's Barry McElduff was 10,342 votes ahead of his nearest challenger, Thomas Buchanan (DUP). 

Barry McElduff later resigned his seat and in the resultant May 2018 by-election, five candidates contested, turnout was 55.13% and Sinn Féin’s Órfhlaith Begley, with 16,346 votes, was 7,956 ahead of her nearest challenger, Thomas Buchanan (DUP). 

The 2019 contest:

Órfhlaith Begley should comfortably retain the seat she won in a by-election last year.

Assembly member Daniel McCrossan (SDLP) has been building his profile, despite the ongoing closure of Stormont. But the main interest in this pro-Remain border constituency will be the margins of difference.

Candidates: Órfhlaith Begley, Sinn Féin; Thomas Buchanan, DUP; Stephen Donnelly, Alliance; Susan Glass, Green Party; James Hope, Aontú; Daniel McCrossan, SDLP; Andy McKane, UUP.


FOYLE 

Outgoing MP: Elisha McCallion (Sinn Féin) 

Brexit referendum result 2016: Remain 78.3%, Leave 21.7 % 

SDLP leader Colum Eastwood and his MLAs leaving Stormont 

The 2017 story:

Turnout was 65.6%, five candidates contested, with 18,256 votes Sinn Féin's Elisha McCallion was 169 votes ahead of her nearest challenger, the outgoing MP, Mark Durkan (SDLP). 

The 2019 contest:

The key nationalist contest - in the home of John Hume and Martin McGuinness, a border constituency.

The highest pro-remain constituency at 78.3% in the Brexit referendum.

Two years ago, three months after the death of Martin McGuinness, Elisha McCallion, a niece of MEP Martina Anderson, ousted former SDLP leader, Mark Durkan. 

He subsequently ran for Fine Gael in the Dublin constituency Euro elections but failed to win a seat. 

Now Colum Eastwood, SDLP leader, tries to regain the Westminster seat for his party. 

How will the Aontú candidate, retired GP Geraldine Donnelly fare? She got 1,000 votes in the May local elections. Who will be affected by her presence? 

Will some unionists 'lend’ their vote to the SDLP and might that orange/green equation be affected by Sinn Féin/SDLP pact arrangements elsewhere? 

Candidates: Colum Eastwood, SDLP; Rachael Ferguson, Alliance; Darren Guy, UUP; Shaun Harkin, People Before Profit; Elisha McCallion, Sinn Féin; Anne McCloskey, Aontú; Gary Middleton, DUP.


EAST LONDONDERRY 

Outgoing MP: Gregory Campbell (DUP) 

Brexit referendum result 2016: Remain 52%, Leave 48% 

DUP MP Gregory Campbell during Féile an Phobail's Leader’s Debate in Belfast

The 2017 story:

Turnout was 61.57%; six candidates contested; with 19,723 votes the DUP's Gregory Campbell was 8,842 votes ahead of his nearest challenger, Dermot Nicholl (Sinn Féin). 

The 2019 contest:

The DUP’s Gregory Campbell should retain his seat in what was a marginally pro-Remain constituency. He received 48% of the votes in a six-candidate contest, two years ago.

Candidates: Gregory Campbell, DUP; Richard Holmes, UUP; Cara Hunter, SDLP; Chris McCaw, Alliance; Seán McNicholl, Aontú; Dermot Nicholl, Sinn Féin.


MID ULSTER 

Outgoing MP: Francie Molloy (Sinn Féin) 

Brexit referendum result 2016: Remain 60.4%, Leave 39.6% 

Órfhlaith Begley and Francie Molloy of Sinn Féin

The 2017 story:

Turnout was 68.59 %; five candidates contested, with 25,455 votes Sinn Féin's Francie Molloy was 12,890 votes ahead of his nearest challenger, Keith Buchanan (DUP). 

The 2019 contest:

The sitting MP, Sinn Féin’s Francie Molloy, should retain his seat with ease.

Candidates: Mel Boyle, Alliance; Keith Buchanan, DUP; Denise Johnston, SDLP; Francie Molloy, Sinn Féin; Conor Rafferty, Independent; Neil Richardson, UUP.


NEWRY AND ARMAGH 

Outgoing MP: Mickey Brady (Sinn Féin) 

Brexit referendum result 2016: Remain 62.9%, Leave 37.1% 

Sinn Fein Westminster 2019 Election candidate Mickey Brady

The 2017 story:

Turnout was 68.87 %; five candidates contested; with 25,666 votes Sinn Féin's Mickey Brady was 12,489 votes ahead of his nearest challenger, William Irwin (DUP). 

The 2019 contest:

Mickey Brady, one of the seven outgoing Sinn Féin MP’s, should comfortably retain his seat. 

An interesting point may be whether Sinn Féin’s abstentionist policy registers in any way in what is a border constituency.

Candidates: Mickey Brady, Sinn Féin; Pete Byrne, SDLP; Jackie Coade, Alliance; William Irwin, DUP; Martin Kelly, Aontú; Sam Nicholson, UUP.