Thatcherism describes the conviction politics, economic, social policy and political style of the British Conservative Party politician Margaret Thatcher, who was leader of her party from 1975 to 1990. It has also been used to describe the beliefs of the British government under Thatcher as Prime Minister from 1979 to 1990, and beyond into the governments of John Major, Tony Blair and David Cameron. An exponent or supporter of Thatcherism is regarded as a Thatcherite.
Thatcherism represented a systematic, decisive rejection and reversal of the post-war consensus, whereby the major political parties largely agreed on the central themes of Keynesianism, the welfare state, nationalised industry, and close regulation of the economy. There was one major exception: the National Health Service, which was widely popular. She promised Britons in 1982, the NHS is "safe in our hands."
Both the exact terms of what makes up Thatcherism as well as its specific legacy in terms of British history over the past decades are controversial. In terms of ideology, Thatcherism has been described by Nigel Lawson, Thatcher's Chancellor of the Exchequer from 1983 to 1989, as a political platform emphasising free markets with restrained government spending and tax cuts coupled with British nationalism both at home and abroad.The Daily Telegraph stated in April 2008 that the programme of the next non-conservative British government, Tony Blair's administration with an emphasis on 'New Labour', basically accepted the central reform measures of Thatcherism such as deregulation, privatisation of key national industries, maintaining a flexible labour market, marginalising the trade unions, and centralising power from local authorities to central government.