this had risen to over 30 million tons The miners, less affected by imported labour or machines than were the cotton mill workers, had begun to form trade unions and fight their grim battle for wages against the coal owners and royalty-lessees. Use of women and children (at a fraction of the cost of men) was common until abolished in an Act of August 1842. In South Wales, the miners showed a high degree of solidarity. They lived in isolated villages where the miners comprised the great majority of workers. There was a high degree of equality in life style; combined with an evangelical religious style based on Methodism, leading to an ideology of egalitarianism. They forged a "community of solidarity" - under the leadership of the Miners Federation. The union supported first the Liberal Party, then after 1918 Labour, with some Communist Party activism at the fringes. Since 1900 The need to maintain coal supplies (a primary energy source) had figured in both world wars. As well as energy supply, coal became a very political issue, due to conditions under which colliers worked and the way they were treated by colliery owners. Much of the 'old Left' of British politics can trace its origins to coal-mining areas, with the main labour union being the Miners' Federation of Great Britain, founded in 1888. The MFGB claimed 600,000 members in 1908. (The MFGB later became the more centralised National Union of Mineworkers). Although other factors were involved, one cause of the UK General Strike of 1926 was concerns colliers had over very dangerous working conditions, reduced pay and longer shifts. Technological development throughout the 19th and 20th centuries helped both to improve the safety of colliers and the productive capacity of collieries they worked. In the late 20th century, improved integration of coal extraction with bulk industries such as electrical generation helped coal maintain its position despite the emergence of alternative energies supplies such as oil, natural gas and, from the late 1950s, nuclear power used for electricity. More recently coal has faced competition from renewable energy sources and bio-fuels. Most of the coal mines in Britain were purchased by the government in 1947 and put under the control of the National Coal Board, with only the smaller mines left in private ownership. The NUM had campaigned for nationalisation for decades and, once it was achieved, sought to work with the