The period of the Labour Government from 1945 to 1950 had been a watershed in British election history. The Government had introduced a raft of major reforms, from welfare state and health service to key measures of nationalisation. The invasion of Egypt in October 1956 had led to Eden's ill-health and resignation, Lord Salisbury had resigned from Macmillan's Government over colonial policy and Peter Thorneycroft over economic policy. In January 1970, the Conservatives had set about detailed preparations for the General Election. The election also marked a period of two-party electoral politics in Britain that was to last until the 1970s. The February 1974 election was a contest held against a background of high drama and industrial conflict. The confrontation between the miners and the Heath Government, combined with the three-day week, led Heath to dissolve in order to seek a fresh mandate for his policy.