The 2017 Northern Ireland Assembly election was held on Thursday, 2 March 2017. The election was held to elect members (MLAs) following the resignation of deputy First Minister Martin McGuinness in protest over the Renewable Heat Incentive scandal. McGuinness' position was not filled, and thus by law his resignation triggered an election.

Eight parties elected MLAs in the sixth assembly: the Democratic Unionist Party (DUP), Sinn Féin, the Ulster Unionist Party (UUP), the Social Democratic and Labour Party (SDLP), the Alliance Party of Northern Ireland, the Greens, People Before Profit (PBP), and Traditional Unionist Voice (TUV). There was also one Independent Unionist MLA.

It was the sixth election since the Assembly was re-established in 1998, and the first to implement a reduction in size to 90 MLAs (versus the previous 108).

1,254,709 people were registered to vote in the election (26,886 fewer, or a 2.1% decrease, compared to the 2016 Assembly election). 64.78% of registered voters turned out to vote in the 2017 Assembly election, up 9.8 percentage points from the previous Assembly election held in 2016, but 5 percentage points less than in the first election to the Assembly held in 1998.

Background Theresa Villiers, Secretary of State for Northern Ireland, announced in 2013 that the next Assembly election would be postponed to May 2016, and would be held at fixed intervals of five years thereafter. Section 7 of the Northern Ireland (Miscellaneous Provisions) Act 2014 specifies that elections will be held on the first Thursday in May in the fifth calendar year following that in which its predecessor was elected, which after 2016 was to be 6 May 2021. However, by virtue of section 31(1) of the Northern Ireland Act 1998, there are several circumstances in which the Assembly can be dissolved before the date scheduled.

Martin McGuinness (Sinn Féin), the deputy First Minister, resigned on 9 January 2017 in protest at the Renewable Heat Incentive scandal (RHI) and other issues, such as the DUP's failure to support funding for inquests into killings during The Troubles and for an Irish language project. The First Minister, Arlene Foster (DUP), had been in charge of the RHI scheme in her previous ministerial position, but had refused to temporarily stand down as First Minister while an enquiry took place. Under the power-sharing arrangement, McGuinness' resignation as deputy First Minister meant that Foster automatically lost office as First Minister. The DUP condemned his resignation.

Sinn Féin had seven days, until 5 pm on 16 January 2017, in which to nominate a new deputy First Minister, but refused to do so in the Assembly plenary on 16 January. As a result, the Secretary of State for Northern Ireland, James Brokenshire, confirmed the same day that a snap election would be held on 2 March.

McGuinness subsequently announced that, owing to ill-health, he would not be seeking re-election to the Assembly; he then stepped down from leading the Sinn Féin group. He was replaced by Michelle O'Neill as leader of Sinn Féin in the Northern Ireland Assembly. Nineteen days after the election, McGuinness died.

Candidates Nominations opened on 27 January 2017 for the assembly election and closed on 8 February 2017.

A total of 228 candidates contested the 90 available seats in the Assembly, a reduction from the 276 who contested the 108 seats available in 2016. The seats were spread over 18 districts, with each district having five seats. The election was conducted using the single transferable vote system.

The table below lists all of the nominated candidates. Candidates for the same party in a constituency are listed in alphabetical order, which is the order they appeared on the ballot paper.

ConstituencyDUPSFSDLPUUPAllianceTUVGreenConOthers Belfast East Mairéad O'Donnell Séamas de Faoite Andy Allen* Andrew Girvin Georgina Milne Sheila BodelBelfast North Nichola Mallon* Robert Foster Nuala McAllister Malachai O'Hara Belfast South Máirtín Ó Muilleoir* Michael Henderson John Hiddleston Clare Bailey* George JabbourBelfast West Frank McCoubrey Alex Attwood* Fred Rogers Sorcha Eastwood Ellen Murray East Antrim Oliver McMullan* Margaret Anne McKillop Ruth Wilson Dawn Patterson Alan DunlopEast Londonderry John Dallat^ William McCandless Chris McCaw Jordan Armstrong Anthony Flynn David HardingFermanagh and South Tyrone Richie McPhillips* Rosemary Barton* Noreen Campbell Alex Elliott Tanya Jones Richard DunnDonal Ó Cófaigh (CCLA)Foyle Gary Middleton* Julia Kee Colm Cavanagh Shannon Downey Stuart CanningLagan Valley Peter Doran Pat Catney Trevor Lunn* Samuel Morrison Dan Barrios-O'Neill Matthew RobinsonMid Ulster Keith Buchanan* Patsy McGlone* Sandra Overend* Fay Watson Hannah Loughrin Stefan Taylor Newry and Armagh William Irwin* Justin McNulty* Danny Kennedy* Jackie Coade Rowan Tunnicliffe Emmet Crossan (CISTA)North Antrim Philip McGuigan* Connor Duncan Robin Swann* Patricia O'Lynn Mark Bailey North Down Kieran Maxwell Caoímhe McNeill Stephen Farry* Steven Agnew* Frank ShiversSouth Antrim Declan Kearney* Roisin Lynch David Ford* Richard Cairns Eleanor Bailey Mark LoganSouth Down Jim Wells* Harold McKee* Patrick Brown Lyle Rea Hannah George Gary HyndsPatrick Clarke (Ind.)Strangford Dermot Kennedy Joe Boyle Kellie Armstrong* Stephen Cooper Ricky Bamford Scott BentonUpper Bann Dolores Kelly^ Tara Doyle Roy Ferguson Simon Lee Ian NicholsColin Craig (WP)West Tyrone Thomas Buchanan* Daniel McCrossan* Alicia Clarke Stephen Donnelly Charlie Chittick Ciaran McClean Roger Lomas

Gerry Mullan, who was an MLA for the SDLP before the dissolution, stood as an independent after having been deselected by the party. Jonathan Bell, who was suspended from the DUP, was also standing as an independent. Both failed to get elected.

Members not seeking re-election

MLA Party ConstituencySydney Anderson Upper BannSammy Douglas Belfast EastAlastair Ross East AntrimMartin McGuinness FoyleCaitríona Ruane South DownCatherine Seeley Upper BannRoss Hussey West Tyrone

Campaign The Renewable Heat Incentive scandal remained central in the campaign. Sinn Féin said they would not return to government with the DUP while questions over RHI remain over the DUP's leader, Foster. There were concerns about deteriorating cross-community relationships. If the two parties emerged as the largest in their communities and could not resolve the issue, direct rule by the UK government could be imposed.

The UUP leader, Mike Nesbitt, promoted the possibility of a UUP/SDLP administration. He said he would give his voting preference after the UUP candidates to the SDLP, although he said he would not tell UUP voters what to do with their later preferences. Other UUP candidates opposed the action, saying they will give later preferences to other unionist candidates over the SDLP, and one UUP councillor resigned from the party in protest.

The DUP criticised Nesbitt's position and campaigned arguing that splitting the unionist vote could help Sinn Féin come out as the largest party.

Brexit was also an issue. In the UK-wide referendum on EU membership on 23 June 2016, 56% of voters in Northern Ireland voted to "Remain" a member of the European Union while 44% voted to "Leave". The DUP supported the UK leaving the EU, while nationalist parties and most others opposed, fearing among other things the possibility of a hard border resulting with the Republic of Ireland.Newsnight, BBC2, 1 March 2017 It became known during the campaign that the DUP spent £282,000 on a pro-Brexit advert in a newspaper that did not appear in Northern Ireland. The money came from the Constitutional Research Council, a minor pro-union group chaired by the former vice-chair of the Scottish Conservative Party Richard Cook.

Position onEuropean Union membership referendum Political parties RefRemainAlliance Party of Northern Ireland Green Party Northern IrelandSinn FéinSocial Democratic and Labour Party (SDLP)Ulster Unionist Party (UUP)LeaveDemocratic Unionist Party (DUP)People Before Profit Alliance (PBP)Traditional Unionist Voice (TUV)

The Alliance Party campaigned on their opposition to sectarianism. People Before Profit focused on their opposition to austerity.

Opinion polling Graphical summary

PollsterClientDate(s)conductedSamplesizeDUP (U)SF (N)UUP (U)SDLP (N)Alliance (O)TUV (U)Green (O)PBP (O)OthersLead 2017 Assembly Election–28.1%27.9%12.9%11.9%9.1%2.6%2.3%1.8%3.7%0.2%Lucid TalkN/A1,58026.3%25.3%13.9%12.2%9.5%4.4%3.4%2.4%2.7%1.0%Lucid TalkN/A1,58025.9%25.1%13.9%12.4%8.9%4.3%3.9%2.7%3.1%0.8%2016 Assembly Election–29.2%24.0%12.6%12.0%7.0%3.4%2.7%2.0%7.1%5.2% * (U): Unionist, (N): Nationalist, (O): Other

Results

Overall results

Seat changes compared to a notional result from 2016 with a 90-seat Assembly Psephologist Nicholas Whyte estimated the likely result in the 2016 election had it been fought with 5-seat constituencies rather than six-seat constituencies. This table shows the different result, and compares the actual result in 2017 to this notional result. Party MLAs elected in 2016 Notional 2016 MLAs elected in 2017 Change from notional 2016 result Designation 383328 5Unionist 282327 4Nationalist 161110 1Unionist 121112 1Nationalist 888Other 222Other 211Other 111Unionist 101 1UnionistTotal1089090

Distribution of seats by constituency

Party affiliation of the five Assembly members returned by each constituency. The first column indicates the party of the Member of the House of Commons (MP) returned by the corresponding parliamentary constituency in the general election of 7 May 2015 (under the "first past the post" method).

2015 MP Constituency Candi-dates Totalseats PBPGreenSinnFéinSDLPAlli-anceUUPDUP TUVInd.Seatgainedby Seat formerlyheld by 1 DUPNorth Antrim–5––1––121––DUP 2 DUP East Antrim–5––––122––UUP SFDUP 3 UUP South Antrim–5––1–112–––DUP 4 DUP Belfast North–5––21––2–––DUP 5 Belfast West–51–4–––––––SDLP 6 SDLPBelfast South–5–1111–1–––DUP 7 DUPBelfast East–5––––212–––DUP 8 Ind. North Down–5–1––112–––DUP 9 DUPStrangford–5––––113–––UUP 10 DUP Lagan Valley–5–––1112–SDLP UUPDUP 11 DUP Upper Bann–5––11–12––SDLP UUPSF 12 SDLP South Down–5––22––1–––UUP 13 Newry and Armagh–5––31––1–––UUP 14 UUP Fermanagh & South Tyrone–5––3––11––SF DUPSDLP 15 West Tyrone–5––31––1–––UUP 16 Mid Ulster–5––31––1–––UUP 17 SDLP Foyle–5––22––1–––PBP 18 DUP East Londonderry–5––11––2–1–DUP18–901227128102811 ––18–10–1––−6−10–––– –1082228128163811–– ––––––––––––– 2181082228128163811–– 256108–1281671836–11 Prog. U.–  108––241862730–11 Prog. U. 1 UKUP  108––182462820–42 Prog. U. 5 UKUP, 2 NIWC

Three of the four independents elected in 1998 ran as Independent Unionists NIWC = Northern Ireland Women's Coalition; Prog. U. = Progressive Unionist Party; TUV = Traditional Unionist Voice; UKUP = UK Unionist Party

Share of first-preference votes

Percentage of each constituency's first-preference votes. Four highest percentages in each constituency shaded; absolute majorities underlined. The constituencies are arranged in the geographic order described for the table above; click the icon next to "Constituency" to see them in alphabetical order.

The totals given here are the sum of all valid ballots cast in each constituency, and the percentages are based on such totals. The turnout percentages in the last column, however, are based upon all ballots cast, which also include anything from twenty to a thousand invalid ballots in each constituency. The total valid ballots' percentage of the eligible electorate can correspondingly differ by 0.1% to 2% from the turnout percentage.