The Clyde Workers Committee was formed to campaign against the Munitions Act. It was originally called the Labour Withholding Committee. The leader of the CWC was Willie Gallacher, who was jailed under the Defence of the Realm Act 1914 together with John Muir for an article in the CWC journal The Worker criticising the First World War.

William Gallacher was a Scottish trade unionist, activist and communist. He was one of the leading figures of the Shop Stewards' Movement in wartime Glasgow and a founding member of the Communist Party of Great Britain. He served two terms in the House of Commons as one of the last Communist Members of Parliament.