For much of its time in office the Labour government struggled with serious economic problems and a precarious majority in the Commons, while the party's internal dissent over Britain's membership of the European Economic Community, which Britain had entered under Edward Heath in 1972, led in 1975 to a national referendum on the issue in which two thirds of the public supported continued membership. Harold Wilson's personal popularity remained reasonably high but he unexpectedly resigned as Prime Minister in 1976 citing health reasons, and was replaced by James Callaghan. The Wilson and Callaghan governments of the 1970s tried to control inflation (which reached 23.7% in 1975) by a policy of wage restraint. This was fairly successful, reducing inflation to 7.4% by 1978. However it led to increasingly strained relations between the government and the trade unions.