Following the results of the general election, we have been analysing different aspects of the results. This Insight looks at which constituencies produced the narrowest or widest victory margins in the 2019 election.

Fewer seats were won by narrow margins in 2019

Of the 650 parliamentary constituencies, 67 seats were won by a margin of 5% or less of votes cast. This is 30 fewer than the 97 won by such narrow margins in the 2017 Election.

The number of very safe seats increased slightly, continuing the upward trend seen in recent elections. Seats won by a margin of over 50% increased from 35 in 2017 to 37 in 2019, while the number of seats won by a margin of between 45% and 50% increased from 29 to 31.

A bar graph showing constituencies grouped by marginality percentage into 5% bands.

The most marginal seats

In the 2019 General Election, 12 seats were won with majorities of less than 1% of valid votes cast (compared with 31 such seats in 2017). A further 14 were won with majorities of between 1% and 2%. These are listed in the table below.

In 2019, only one seat (Fermanagh and South Tyrone) had a victory margin of less than 100 votes, compared with 11 such seats in 2017.

Back in 2017 Scotland accounted for 12 out of the 31 seats with victory margins of less than 1%. This time around, only two Scottish seats were won by this margin. The tightest contest in Scotland was in East Dunbartonshire, where the then Liberal Democrat leader Jo Swinson lost the seat to the SNP by 149 votes (0.28%).

Of the 36 seats won by less than 2%, eight were Conservative gains from Labour, and seven were contests in which Labour fended off a Conservative challenger.

A table showing the 26 seats won by majorities of less than 2%. Number one is Fermanagh and South Tyrone and number 26 is Blyth Valley.

Across the UK, 141 seats out of 650 were won by a margin of less than 10 percentage points. The map below shows where these are located. 22 of the 141 (16%) are in Scotland, accounting for 37% of Scottish constituencies, and 21 of them (15%) are in the Yorkshire and the Humber region, accounting for 39% of constituencies in that region. The lowest concentrations of marginal seats are in the South West and the East of England.

A map showing the 141 constituencies out of 650 (22%) were won by margins of less than 10%.

The safest seats

For the fourth general election in a row, Liverpool Walton and Knowsley are the first and second-safest seats respectively in terms of victory margin as a percentage of all valid votes cast. In terms of number of votes however, Knowsley is the safest – as it was in 2017.

The table below shows the 30 safest seats in the UK in percentage terms. As was the case in 2017, the top five are all in Merseyside. Whereas in the 2017 Election 29 of the top 30 were Labour holds, this time around 20 are Labour holds and 10 are Conservative holds. The 18 safest seats in percentage terms were won by margins of over 60% of valid votes cast.

A table showing the thirty safest seats in percentage terms. Number one was Liverpool, Walton (Labour hold). Number 30 was Brentwood and Ongar (Conservative hold).

Three-way marginals

The 2017 General Election produced a remarkable number of three-way marginals, especially in Scotland. In 37 seats (of which 30 were in Scotland) the vote-share gap between first and third place was less than 20 percentage points. In eight of these seats (seven in Scotland) the gap was less than 10 percentage points.

In the 2019 election however, the number of three-way marginals greatly diminished, and those that did occur were not so concentrated in one part of the UK. 17 seats had a vote-share gap between first and third place of less than 20 percentage points and only three of these had a gap of less than 10 percentage points. The 20 closest three-way marginals in the 2019 General Election are shown in the table below.

The Brexit Party was involved in five of the top 20 three-way marginals. In all five of these seats, Labour won and the Conservatives occupied the other spot in the top three.

In three of the London seats featuring in the top 20, the Liberal Democrats’ vote share appeared to be boosted by the candidacy of high-profile defectors from other parties:

  • Chuka Umunna (ex-Labour) in Cities of London and Westminster (Lib Dem share up from 11.0% in 2017 to 30.7% in 2019)
  • Sam Gyimah (ex-Conservative) in Kensington (Lib Dem share up from 12.2% in 2017 to 21.3% in 2019)
  • Luciana Berger (ex-Labour) in Finchley and Golders Green (Lib Dem share up from 6.6% in 2017 to 31.9% in 2019).
A table showing the 20 seats with the narrowest margin between 1st and 3rd place. Number 1 is Ynys Mon and number 20 is Normanton, Pontefract and Castleford.

Further reading

General Election 2019: full results and analysis, House of Commons Library.

Who stood in the General Election 2019? House of Commons Library.

About the author: Rod McInnes is a researcher at the House of Commons Library specialising in social and general statistics.