Within his first year of work, he took part in a lengthy strike, and as a result, was allowed to join the Basford and District Hosiery Trimmers' and Finishers' Society, despite being under the usual age for admission.
[1] Charlesworth joined the Communist Party of Great Britain in 1930, and although he did not keep this a secret, it did not initially impede his trade unionism.
The union was in a poor financial position, losing members, and faced disputes between its men's and women's sections.
[2] Charlesworth managed to almost double membership, to 3,500, and resolve the disputes, but he believed that the various local hosiery unions should merge.
[1] Charlesworth was elected as secretary of the Nottingham and District Trades Council in 1950, focusing on industrial affairs, peace, and opposition to racism.