The Union of Democratic Mineworkers is a British trade union based in Nottinghamshire, England, established in 1985 after a constitutional crisis in the National Union of Mineworkers. The UDM was given its certification on 6th December 1985, although it had effectively been in existence since the Nottinghamshire area of the NUM voted to secede from the federal union on 6th July 1985. After the events of the strike in 1984-5, the Nottinghamshire area of the NUM was involved in a number of disputes with the National Executive Committee that led to a ballot in May on empowering the Nottingham Area Committee to disassociate from the NUM. In ballots on 18th and 19th October on joining with Nottinghamshire in a new union, the South Derbyshire area of the NUM voted in favour by 51% and the Collie