Scottish Parliament election marginal constituencies

FFS explains: marginal constituencies and regional unknowns

The 2021 Scottish Parliament election will see candidates and parties fighting over both constituencies and list seats.

While the SNP has a significant lead in the number of MSPs, there are aspects of the election that remain on a knife edge. A number of constituency seats were won by fewer than 1,000 votes in 2016, and some smaller parties are pinning their hopes on gaining representation through the regional list.

Ferret Fact Service examined where parties will be looking to pick up seats in the vote on 6 May.

How close will it be?

Nicola Sturgeon’s party are four seats short of a majority and polling shows the party may be close to achieving that goal, which would see them no longer reliant on support from the Scottish Greens and others to pass legislation at Holyrood.

For the opposition parties, depriving the SNP of that majority may be the aim, as well as the battle for second place.

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The Scottish Conservatives overtook Scottish Labour as the main opposition party in 2016, securing second place by seven seats. New Labour leader Anas Sarwar is aiming to retake that position.

For the Scottish Greens and Scottish Liberal Democrats, an increase in MSPs will be considered a success. The two parties have the same number of representatives in parliament after Andy Wightman left the Greens in 2020 to sit as an independent.

What are the closest constituencies?


Dumbarton is the closest constituency in Scotland, with Labour’s Jackie Baillie holding the seat by just 109 votes in the 2016 election. She has been the incumbent since 1999 but has seen her majority whittled down. Her challenge comes from the SNP, and their candidate, Toni Giugliano. She held onto her seat in 2016 despite a national swing towards the SNP, with many citing her campaigning in support of the constituency’s HMNB Clyde, also known as Faslane, where the UK’s Trident nuclear missiles are stored.

Winner: Jackie Baillie – Scottish Labour – 13,522 votes

Second place: SNP – 13,413 votes

Majority: 109 votes

Edinburgh Central

Former Scottish Conservatives leader Ruth Davidson is the incumbent MSP in Edinburgh Central, which she took from the SNP in a massive swing to the Tories in 2016. She is stepping down from the seat in the 2021 election, replaced as a candidate by Scott Douglas. He is facing a significant challenge in former SNP Westminster leader Angus Robertson.

Winner: Ruth Davidson – Scottish Conservatives – 10,399 votes

Second Place: SNP – 9,789 votes

Majority: 610 votes


Ayr is the third closest run constituency by number of votes, with just 750 separating the incumbent Conservatives and the SNP. John Scott has held the seat since winning it from Labour in a by-election 21 years ago. Recent elections have seen Scott’s majority getting narrower, and the Scottish Conservatives will be keen to hold on to one of their most resilient areas of support in Scotland, and longest-serving MSP.

Winner: John Scott – Scottish Conservatives – 16,183 votes

Second Place: SNP – 15,433 votes

Majority: 750 votes

Aberdeenshire West

Another constituency where the SNP will be looking to pick up a constituency seat is Aberdeenshire West, currently held by the Scottish Conservatives by a margin of 900 votes. Previously an SNP seat after the 2011 election, the constituency was won by the Tories’ Alexander Burnett in a swing of 12 per cent.

Winner: Alexander Burnett – Scottish Conservatives – 13,400 votes

Second Place: SNP – 12,500 votes

Majority: 900 votes

What about the regional list?

One of the biggest questions this election is how the parties will perform on the regional list.

The 6 May vote will see parties picking up seats in both constituencies and regions, via the additional members system.

While the constituency vote is based on the first past the post system used in UK Parliament elections, the regional vote via a form of proportional representation. Scotland is divided into eight regions, electing seven MSPs each.

They are then elected based on a system known as the D’Hondt formula. This balances votes in the regional list against success in the constituency vote, meaning it should be harder for a party which takes seats in the region’s constituencies to gain seats on the list. This aims to give better representation to smaller parties which would otherwise not return MSPs reflective of their vote share.

This means the most successful party in the constituency vote, likely to be the SNP, may struggle to gain MSPs through the list. In the 2016 election the party won 59 of 73 constituencies, but returned only four regional MSPs, despite receiving nearly twice as many votes (41.7 per cent) on the list as its nearest challenger.

In 2016, the second and third largest parties – Scottish Conservatives and Scottish Labour – gained most of their seats through the regional vote instead of constituencies. The Scottish Greens had six MSPs elected through the regional list, accounting for all its representation.

How about the new list parties?

This election there are a number of smaller parties vying for seats on the list, who previously have not been represented. The two highest-profile are Alex Salmond’s Alba Party, and All4Unity, fronted by George Galloway. Both parties could be within striking distance of gaining seats on the list.

The threshold for gaining representation on the regional vote is around five to six per cent, although this depends on the region and how the rest of the votes are distributed among the other parties.

The usual margin of error for election opinion polls is about three per cent, and both Alba and All4Unity have polled within the margin of error of the usual threshold for seats, so their impact remains to be seen.

Ferret Fact Service (FFS) is a non-partisan fact checker, and a signatory to the International Fact-Checking Network fact-checkers’ code of principles. All the sources used in our checks are publicly available and the FFS fact-checking methodology can be viewed here. Want to suggest a fact check? Go to, email us at or join our Facebook group.

Photo thanks to Fraser Bremner/Scottish Daily Mail

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