The seat had become vacant when the constituency's Labour Member of Parliament (MP), Keir Hardie, died on 26 September 1915, aged 59.
The selection procedure quickly became a battle between competing factions of the Independent Labour Party, played out within the administrative structures of the SWMF.
[citation needed] Following the result of the selection, Stanton resigned as a miners' agent and fought the election as a pro-war 'National' candidate.
Stanton fought the Aberdare seat and won it by a larger majority, defeating the pacifist Labour candidate Thomas Evan Nicholas.
The British Workers League had transformed itself into the National Democratic and Labour Party and Stanton stood under its label, with the Coalition Coupon.