He was a member of the Conservative Party, and was selected as the official candidate of the Wartime Coalition for the West Derbyshire by-election on 18 February 1944, in the constituency local to Chatsworth. He was faced by Charles Frederick White, Jr., who resigned from the Labour Party to run as an Independent candidate, evading the Wartime Coalition's ban on partisan campaigning. West Derbyshire had been held by Conservatives since 1923 (Hartington's father and then his uncle by marriage). In a contentious campaign, White solidly defeated Hartington with 57.7% of the vote to 41.5%.[3]
Second World War and death
He received a commission as an officer into the British Army's Coldstream Guards regiment during the Second World War. In August 1944, during the liberation of Europe in the West from Nazi Germany, Hartington's unit, the 5th Battalion Coldstream Guards, as a part of the Guards Armoured Division, was engaged in heavy fighting in France. In early September 1944, it crossed the River Somme and pushed Eastward towards Brussels, where it was one of the first to liberate the city. Of the townsfolk and villagers who turned out and cheered the Allies and, in some cases, decorated their tanks, Hartington wrote to his wife of feeling "so unworthy of it all living as I have in reasonable safety and comfort during these years..... I have a permanent lump in my throat and long for you to be here as it is an experience which few can have and which I would love to share with you."[4]
^'HARTINGTON, Marquess of', Who Was Who, A & C Black, an imprint of Bloomsbury Publishing plc, 1920–2015; online edn, Oxford University Press, 2014 ; online edn, April 2014 accessed 26 Aug 2015