The seat became vacant when the Labour Member of Parliament (MP) William Lunn died on 17 May 1942, aged 69.
Lunn had held the seat since its creation for the 1918 general election.
The Labour Party selected as its candidate Alderman Thomas Brooks MBE, a miner and trade union organiser who had been a local councillor since 1914.
(The most recent had been Maldon in June 1942, where an independent Labour candidate won what had previously been a safe seat for the Conservatives).
He held the Rothwell seat until the constituency's abolition for the 1950 general election.