Born in Camberwell, Rust began working at Hulton's Press Agency before moving to the Workers Dreadnought newspaper produced by Sylvia Pankhurst.

[2] In 1925, Rust was one of 12 members of the Communist Party convicted at the Old Bailey under the Incitement to Mutiny Act 1797, and was given 12 months' imprisonment.

He was in the post for two years, before becoming the CPGB's representative in Moscow, then after a period as a party organiser in Lancashire, he became the Daily Worker's correspondent with the International Brigades in the Spanish Civil War.

Their daughter Rosa remained until the 1940s, was caught up in the 1941 ethnic cleansing of the Volga Germans, then spent time in forced labour camps before being allowed to return to Britain in 1943.

[5] Rust was married a second time to Tamara Kravetz, who, following his death, was remarried, in 1954, to Wogan Philipps, who acceded to his father's peerage as 2nd Baron Milford in 1962 and became the only Communist to sit in the House of Lords.