There was a by-election for the United Kingdom House of Commons in Hamilton on Wednesday 31 May 1978. It was caused by the death of the incumbent Labour Party Member of Parliament Alex Wilson on 23 March of that year.
The by-election was the last in the UK to date not held on a Thursday. This was because the opening game of the 1978 FIFA World Cup was on Thursday 1 June.
The Labour candidate was George Robertson, who defeated a strong SNP candidate Margo MacDonald, with an increased majority.
It was one of a series of significant Labour victories over the SNP in 1978 which halted their rise at that time.
References
Hamilton by-election, 1978 Wikipedia(Text) CC BY-SA