LONDON (Reuters) -British Prime Minister Keir Starmer's Labour Party won a surprise victory in a fiercely fought by-election for the Scottish parliament on Friday after one of the most bitter election campaigns in the country's recent history.

The by-election, triggered by the death of sitting SNP MSP Christina McKelvie, was dominated by the rise of Reform, which has been garnering increasing support in council by-elections in Scotland, albeit at lower levels than in England and Wales.

But there are "some caveats". Labour won a Westminster by-election there less than two years ago with a majority of about 9,500 and triumphed at the 2024 general election by a "similar margin", but this time they "squeaked through" on a "thin margin" margin of 602 votes.