He came to prominence in the early 1970s when he led the Upper Clyde Shipbuilders Work-in top try and stop the Edward Heath Tory government from closing down the shipyards on the River Clyde. An engineer to trade, and a union official Reid, along with his colleague Jimmy Airlie decided that the best way to show the viability of keeping the yards open was by staging a 'work-in' rather than going on strike. The campaign was successful in persuading Heath to back down.
Reid was at this stage a member of the Communist Party of Great Britain and was a councillor in Clydebank. He also received the last respectable number of votes for any communist candidate for a House of Commons seat when he polled over 6,000 votes in the Clydebank constituency.
Reid also served as Rector of the University of Glasgow, being elected in 1972, largely on the back of his union activities.
He later moderated his political position and joined the Labour Party and was a candidate for them in Dundee East, but lost against the then Scottish National Party (SNP) leader Gordon Wilson.
Reid became a journalist, writing opinion columns for various newspapers, including The Daily Mirror, The Herald and The Scotsman. He also did some work for television. In 2000 he helped establish the Scottish Left Review, a bi-monthly publication.
Reid continued to support Labour up till the 1997 General Election, but thereafter became disillusioned with the New Labour phenomenon and has since urged people to support either the SNP or the Scottish Socialist Party (SSP).