SNP on track for Holyrood landslide on 35% vote

The Herald Scotland

24-05-2025

Using the Gallagher Index – a standard international measure of electoral disproportionality – Mr McGeoghegan found the 2026 Scottish Parliament election would score 27.3 for constituency seats alone. He said this would be the third–highest level of distortion globally if it occurred in a national election.
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The current Additional Member System (AMS) used to elect MSPs combines first–past–the–post constituencies with a proportional top–up via regional lists.
But Mr McGeoghegan warned that the balance has become increasingly skewed, particularly as the political landscape fragments and the pro–union vote is divided among multiple parties.
Writing in The Herald, he said: 'This disproportionality is almost entirely a result of the first–past–the–post component of Holyrood's electoral system. The SNP are set to win just short of 60 of [the 73 constituency seats] – 82% of the seats on a 35% vote share.'
The total Gallagher Index score for the full 2026 election is projected at 11.2 – more than 50% higher than the 7.1 recorded in 2011, when the SNP won a majority under a system designed to prevent any one party from doing so.
The warning follows what has been described as the most disproportionate general election in British history. Labour won 63 per cent of seats at Westminster on just 34% of the vote, with a Gallagher Index score of 23.6 – higher than any UK election before it.
The Electoral Reform Society said 16.6 million voters were now 'unrepresented' as a result.
While the level of distortion in Scotland is not as extreme, the consequences could still be profound. According to Mr McGeoghegan, the likely result in 2026 is a pro–independence majority in Parliament – even if most voters back unionist parties.
'There is something grimly ironic about this,' he wrote. 'Holyrood's electoral system is a creature of Labour's creation. The lopsided Additional Member System, skewed towards constituency MSPs, was a compromise intended to keep power in Labour's hands. But… it now functions to keep power in the SNP's hands instead.'
He added: 'If the SNP remain in power after next May, which they are likely to do, it will be thanks to the constituency vote. They are set to lose just four seats compared to the 2021 election, despite their vote share falling by around a third.'
Responding to the research, Willie Sullivan of the Electoral Reform Society said the system could be improved, but was far better than the alternative.
He said: 'My initial thoughts on this are thank God we do not have a first–past–the–post system for Scottish elections. We would be seeing large majority governments on nowhere near majority votes – and as the projection shows, no majority is expected in Scotland next year.
'As you know, it is an associative world, so it is important to be careful when suggesting a system that gives a huge majority on 34% of the vote is even in the ballpark as an election or system where the largest party will likely fail to get a majority on a similar or higher vote share.
"Armed robbery and shoplifting are both theft – but they are not really the same thing.
'AMS does give much more representative results in multi–party systems, so is a vast improvement on FPTP. It is relatively very good, but could always be made better.
'The split in FPTP to the regional lists that adjust to make the result more proportional is 50 per cent to 45 per cent – and if it was wanted to make it more proportional, that could be 50/50.
'Also, the formula for calculating the top–up might be changed from D'Hondt to Sainte–Laguë, as D'Hondt does tend to provide a bit of a largest–party or winner bonus. In theory, these changes could be made fairly easily.'