General Election 2017

UK General Election 2017 — Full Results

Q: Why did Theresa May lose her majority in 2017?

Theresa May called the 2017 election expecting to increase her majority ahead of Brexit negotiations. Her campaign was widely considered disastrous — her manifesto included an unpopular social care policy quickly reversed, she refused to participate in leaders' debates, and her campaign slogan strong and stable became a punchline. Jeremy Corbyn outperformed expectations, energising young voters and running a positive campaign.

Q: What was the significance of Corbyn's 2017 campaign?

Corbyn's 2017 performance is widely seen as demonstrating that a left-wing Labour platform can attract significant voter support against a weak opponent. Labour won 40% of the vote — the highest Labour share since 2001 — energising young voters and running the biggest increase in Labour vote share since 1945. However, the hung parliament and subsequent 2019 defeat tempered its significance as a validation of the Corbyn project.

Q: What was the DUP confidence and supply arrangement in 2017?

Following the 2017 hung parliament, Theresa May's Conservatives entered a confidence and supply agreement with the Democratic Unionist Party (DUP), Northern Ireland's largest unionist party holding 10 MPs. The DUP would support the government in confidence votes and budget votes in exchange for £1 billion in additional spending for Northern Ireland. The arrangement was deeply controversial — the money was widely seen as a political price — and proved unstable. DUP opposition to May's Brexit deal contributed to her parliamentary defeats, ultimately forcing her resignation in 2019.

8 June 2017: Theresa May's gamble fails. Labour surges to 40% under Corbyn. No overall majority — Conservatives form minority government with DUP confidence and supply.

317

Conservative seats

262

Labour seats

No majority

326 needed

8 June 2017

Polling day

68.7%

National turnout (+2.6%)

Snap

Called by Theresa May

Brexit

Dominant issue

Full Party Results

Party	Vote Share	Change vs 2015	Seats Won	Seats Change
Conservative	42.4%	+5.5%	317	+12
Labour	40.0%	+9.6%	262	+30
SNP	3.0%	-1.7%	35	-6
Lib Democrats	7.4%	+0.5%	12	+4
DUP	0.9%	+0.3%	10	+2
Sinn Fein	0.7%	+0.1%	7	+3
Plaid Cymru	0.5%	+0.1%	4	0
Greens	1.6%	-2.0%	1	-1
UKIP	1.8%	-10.8%	0	-1
Others	1.7%	n/a	3	n/a

Source: Electoral Commission. UKIP collapsed to 1.8% — their 2015 vote went primarily to Conservatives.

The Corbyn Surge: How Did It Happen?

The campaign transformation

At the start of the campaign, polls gave the Conservatives a 20+ point lead. Theresa May refused to debate Corbyn directly. Labour's manifesto — which included free university tuition, renationalisation and rent controls — was costed and popular with younger voters. Corbyn proved an effective campaign trail performer, drawing large crowds in unexpected places.

Youth turnout surge

There was a significant increase in youth registration and turnout in 2017, driven partly by Jeremy Corbyn's appeal and the policy on tuition fees. Universities and urban areas saw some of the largest swings to Labour, with seats like Canterbury — held by Conservatives since 1918 — falling to Labour. Estimates suggest 18–24 year old turnout increased by around 10 percentage points.

May's catastrophic manifesto

The Conservative manifesto contained a proposal for social care reform — quickly dubbed the "Dementia Tax" — that would require elderly homeowners to sell their properties to fund care costs. The backlash was immediate and significant, forcing a U-turn within days. The episode undermined May's core message of "strong and stable" leadership and is widely seen as a pivotal moment in the campaign's collapse.

UKIP's collapse helps both parties

UKIP fell from 12.6% in 2015 to just 1.8% in 2017 — a collapse of over 10 points. Crucially, the UKIP vote split both ways: Leave-identifying UKIP voters in Labour heartlands moved to the Conservatives (helping May in Wales and the North), while others moved back to Labour. The net effect was smaller than many expected, leaving both main parties with substantial vote totals.

The Near-Hung Parliament

55 seats: the gap between government and the edge of power

Theresa May entered the election with 330 seats and a small majority. She won 317 — 9 fewer. Labour gained 30 seats. The result left no party with the 326 needed for an outright majority. May formed a minority government supported by the Democratic Unionist Party (DUP) through a confidence and supply agreement, paying the DUP £1 billion in additional spending for Northern Ireland in exchange for their 10 votes. The arrangement was deeply unpopular and contributed to the instability that defined the 2017–2019 Parliament.

317

Con seats (needed 326)

DUP seats (supplied majority)

262

Labour seats (highest since 2005)

2.4%

Con-Lab vote margin (closest since 1974)

2017 vs 2019: Labour's Collapse

From near-victory to worst result since 1935 — in two years

Labour's 40% vote and 262 seats in 2017 represented a significant achievement for Corbyn. By 2019, that had collapsed to 32.1% and 202 seats — a loss of 60 seats. The key changes: Brexit crystallised cultural and political divides, Labour's confused Brexit position alienated both Remain and Leave voters, and the Conservatives under Boris Johnson had a clear, simple message. The anti-semitism crisis and Corbyn's net approval rating — deeply negative by 2019 — were also significant factors. It remains one of the most dramatic two-election swings in modern British political history.

Party	2017 Vote	2019 Vote	Vote Change	2017 Seats	2019 Seats
Conservative	42.4%	43.6%	+1.2%	317	365
Labour	40.0%	32.1%	-7.9%	262	202
Lib Dems	7.4%	11.6%	+4.2%	12	11
SNP	3.0%	3.9%	+0.9%	35	48
UKIP/Brexit	1.8%	2.0%	+0.2%	0	0
Greens	1.6%	2.7%	+1.1%	1	1

Frequently Asked Questions

What was the result of the 2017 UK General Election?

Theresa May's June 2017 snap election resulted in a hung parliament. The Conservatives won 317 seats with 42.4% — short of the 326 needed for a majority. Labour under Jeremy Corbyn surged to 262 seats with 40.0%, reversing 20-point poll deficits during the campaign. May subsequently formed a confidence-and-supply arrangement with the DUP's 10 MPs to remain in government. The result was widely seen as a catastrophic miscalculation by May, who had entered the election expecting a significantly enhanced majority.

Why did Theresa May lose her majority in 2017?

May called the 2017 election expecting to increase her majority ahead of Brexit negotiations. Her campaign was widely considered disastrous: the manifesto included an unpopular social care proposal (quickly dubbed the "Dementia Tax") that required a humiliating U-turn within days; she refused to participate in leaders' debates; and her campaign slogan "strong and stable" became a punchline. Jeremy Corbyn outperformed all expectations, energising younger voters with a positive, costed manifesto and large campaign rallies.

What was the significance of Corbyn's 2017 campaign?

Corbyn's 2017 performance demonstrated that a left-wing Labour platform could attract significant support against a weak opponent. Labour won 40% — the highest Labour vote share since 2001 — and the largest single-election increase in Labour vote share since 1945. The campaign energised young voters with policies on tuition fees and housing. However, the subsequent 2019 collapse to 32.1% and the loss of 60 seats revealed that 2017's result reflected Conservative weakness as much as Labour strength.

What was the DUP confidence and supply arrangement in 2017?

Following the hung parliament, Theresa May's Conservatives entered a confidence and supply agreement with the Democratic Unionist Party, Northern Ireland's largest unionist party holding 10 MPs. The DUP would support the government in confidence votes and on the budget in exchange for £1 billion in additional spending for Northern Ireland — a deal widely criticised as a political payment. The arrangement proved unstable: DUP opposition to May's Brexit deal contributed directly to her parliamentary defeats and eventual resignation in 2019.

How did 2017 shape both the Conservative and Labour parties?

For the Conservatives, losing the majority created a poisoned parliament: unable to pass Brexit legislation without DUP or rebel backbench support, paralysed by internal splits, ultimately requiring two leadership changes. This directly led to the 2019 election. For Labour, 2017 was energising but misleading — the Corbyn project seemed validated by 40%, encouraging the party to contest 2019 on similar terms, with disastrous results. The real lesson — that Conservative policy errors and a weak opponent inflated the 2017 result — was only clear in retrospect.

How does 2017's two-party dominance compare to 2026 polling?

The 2017 election saw the two main parties win a combined 82.4% of the national vote — the highest two-party share since 1970. In 2026 polling, Labour and Conservatives combined account for approximately 37%, with Reform UK at 28%, Greens at 15% and Lib Dems at 11%. This collapse of two-party politics represents the most dramatic fragmentation of the British electoral landscape in modern history, driven by post-Brexit cultural realignment, institutional distrust and Reform UK's rise as a genuine third force challenging both major parties across England and Wales.

Sources & Further Reading

Official 2017 results data is available from the House of Commons Library: 2017 General Election statistics. Compare with the 2019 results and the 2024 results to track the shift from Labour-Conservative two-party politics.