Labour has represented the seat of Hemsworth since its creation in 1918, and from 1966 to 1974 held it with the largest majority of any party in the UK. From 1950 to 1974 Labour’s share of the vote never dropped below 80 per cent. That it is now a marginal seat is regarded as partly due to the disappearance of the coal mining industry, the reorganisation of Conservative-voting areas of the southern part of Wakefield into the constituency in 2010 and the prominence of Brexit as an election issue in 2019. It is estimated that 68.1 per cent of the constituency voted leave in the EU referendum of 2016.