Born in Rothwell, Lunn began working as a coal miner when he was twelve years old.
[1] Lunn was a supporter of the Labour Party, and served on Rothwell Urban District Council and the Hunslet Board of Guardians.
[1] When the Second Labour Government took office in June 1929, Lunn was appointed as Under-Secretary of State for the Colonies.
He was moved in December that year to the post of Under-Secretary of State for Dominion Affairs, and held that position until the formation of the National Government in August 1931.
[1] In July 1936, during a debate on the Government's Midwives Bill, Lunn referred to the death of his daughter-in-law, earlier that day, when arguing for more to be done to protect the health of mothers.