The Grunwick dispute began in August 1976 when 137 workers, mainly South Asian women, walked out of the Grunwick film processing plant in Willesden, north-east London. The dispute centred on the poor conditions and lack of union recognition at Grunwick and involved the Association of Professional, Executive, Clerical and Computer Staff union (APEX), which represented the strikers. It lasted almost 2 years, with allegations of violence and intimidation from both strikers and management, and became a cause celebre for the union movement and its opponents. The UPW became involved when its members refused to deliver post to and from the Grunwick plant. After the National Association for Freedom (NAFF) took legal action against the UPW for breaching the 1953 Post Office Act, it was agreed that the postal service would resume. Unofficial 'blacking' of the Grunwick post later restarted, resulting in the suspension of workers at Cricklewood by the Post Office.
[See MSS.464 for further archival material relating to the Grunwick dispute].