In 1910, Lindsley was selected to contest Barkston Ash for the Labour Party. He ultimately withdrew his candidacy, but was selected as Prospective Parliamentary Candidate for Dumfries Burghs in 1911. Due to the outbreak of World War I, no election was held until 1918, and by that time, Lindsley's political views had changed. A strong supporter of British involvement in the war, he resigned from the ILP, and joined the National Democratic and Labour Party (NDP), standing unsuccessfully for it in Houghton-le-Spring.
