The Ashton-under-Lyne by-election was held on 29 October 1928. It was notable for having the highest turnout of any Parliamentary by-election in Great Britain. The election was caused by the bankruptcy of Conservative Party Member of Parliament for Ashton-under-Lyne Cornelius Homan. Although Homan had only represented the constituency since the 1924 general election, Ashton had been represented by Conservatives for many years, and Labour had never taken the seat. However, the Conservatives had never achieved a large majority in the seat, and as both Labour and the Liberal Party had gained several seats in recent by-elections, it was thought that both would mount a strong challenge. As a result, interest in the by-election was high.