The UK miners' strike of 1984-85 was a major industrial action affecting the UK coal industry. The strike by the National Union of Mineworkers (NUM) was led by Arthur Scargill, although some NUM members considered it to be unconstitutional and did not observe it. The BBC has referred to the strike as "the most bitter industrial dispute in British history." At its height, the strike involved 142,000 mineworkers, making it the biggest since the 1926 General Strike.