In the 1999 Scottish parliamentary election the seat had been the most marginal in Scotland, with Labour winning over the Conservatives by a mere 25 votes.

[3] The result was a poor one for the Scottish Labour, which had won the seat in the previous year, albeit with a majority of just 25.

This by-election showed a strange effect in the Scottish AMS electoral system.

Labour in the South of Scotland region had won seven seats, all as first past the post constituencies and none on the list system through proportional representation, whilst the Conservative and Unionists had won four seats in South of Scotland through the proportional representation system.

By winning the Ayr seat at the by-election the Conservatives had technically greater representation than their 1999 results would have proportionally given them.