A summer UK general election may have been a surprise, but Northern Ireland's political parties have been preparing for this campaign for some time.
Some constituencies are much more competitive than others.
By Friday morning, the votes will be counted and the results announced in what is yet another defining week for politics in Northern Ireland.
Belfast East
In Belfast East two political titans - Gavin Robinson and Naomi Long - are locked in a battle that could have far wider implications than who represents the constituency in the House of Commons.
Belfast North
Sinn Féin's John Finucane became the first nationalist to win the North Belfast seat when he defeated the DUP's Nigel Dodds, who had held it for 18 years - five years on he is the favourite to retain it.
Belfast South and Mid Down
With no Sinn Féin candidate standing, sitting SDLP MP Claire Hanna looks to have a clear run at returning to Westminster for Belfast South and Mid Down.
Belfast West
Sinn Féin has held Belfast West since 1992 and more than three decades on it may see the majority of over 14,000 votes slip, but there is little fear of Paul Maskey losing his seat.
East Antrim
It will be a real shock if the DUP's Sammy Wilson does not retain the East Antrim seat he has held since 2005, and the focus may be on whether the Ulster Unionists can stem the electoral surge of the Alliance Party in recent years and regain second place.
East Londonderry
Outgoing MP Gregory Campbell of the DUP has represented East Londonderry, which is the official name of the constituency, since 2001 and it would be a major upset if he is not back in the House of Commons again.
Fermanagh South Tyrone
Two candidates representing two communities – Sinn Féin's Pat Cullen and Diana Armstrong of the UUP - will both be hoping to come out on top in Fermanagh South Tyrone in what is regarded as the most marginal seat across the UK.
Foyle
SDLP leader Colum Eastwood has gone on record saying his political career would be over if he loses the Foyle seat he won with a majority of more than 17,000 votes in 2019. Few expect him to be looking for a new job on 5 July .
Lagan Valley
The resignation of Jeffrey Donaldson as DUP leader after being charged with serious sexual offences, which he denies, has changed everything in Lagan Valley, with the Alliance Party now believing it has a real chance to cause an upset while the Ulster Unionists insist they are also in the running.
Mid Ulster
The Westminster seat for the Mid Ulster constituency has been in Sinn Féin's hands since 2013, and that is expected to remain the case with Francie Molloy set to pass the baton to Cathal Mallaghan.
Newry and Armagh
Mickey Brady, who has held the Newry and Armagh seat for Sinn Féin since 2015 is stepping down, but his replacement - Dáire Hughes – is expected to hold this seat this time around.
North Down
Alliance's Stephen Farry will be hoping to hold onto the North Down seat he won in 2019, but will face a stiff challenge from former DUP and now Independent candidate Alex Easton.
South Antrim
In a constituency that has only ever returned a unionist MP it looks set to be an intriguing battle between DUP incumbent Paul Girvan and the UUP's former Stormont health minister, Robin Swann, to represent South Antrim.
South Down
Sinn Féin Chris Hazzard won out over the SDLP in South Down with a 1,600 majority in 2019 and he'll be hoping to retain it, but tactical voting by unionists and boundary changes might add to the sum of the SDLP vote.
Strangford
Strangford has been viewed as a shoo-in for the DUP for the past two decades but is expected to be a more competitive contest this time around and the party will be wary of the possible double whammy of an Alliance bounce and a strong TUV performance.
North Antrim
This is a seat that has been synonymous with the Paisley name for decades - in fact it has been in the family since 1970 - and while Ian Paisley Jr will face a challenge from TUV leader Jim Allister there is little prospect of change this time around in North Antrim.
Upper Bann
The DUP's Carla Lockhart goes into this election with an 8,200 vote majority over Sinn Féin and no challenge from the right of unionism in Upper Bann.
West Tyrone
The youngest Westminster constituency in Northern Ireland, having been created in 1997, is also one of the most predictable - apart from an Ulster Unionist victory in the year of its birth, this has been a Sinn Féin seat, and the party has polled just over 40% of the vote share in West Tyrone in every General Election since 2010.
