Margaret Thatcher was elected Member of Parliament for Finchley in 1959. Edward Heath appointed her Secretary of State for Education and Science in his Conservative government. In 1975, Thatcher defeated Heath in the Conservative Party leadership election to become Leader of the Opposition, the first woman to lead a major political party in the United Kingdom. She became Prime Minister after winning the 1979 general election. Thatcher introduced a series of economic policies intended to reverse high unemployment and Britain's struggles in the wake of the Winter of Discontent and an ongoing recession. Her political philosophy and economic policies emphasised deregulation (particularly
Premiership of Margaret Thatcher her opposition to greater economic integration into the European Community. She also alienated many Conservative voters and Members of Parliament with the imposition of the local poll tax. As her support fell away, she was challenged for the party leadership and persuaded by her Cabinet to withdraw from the second round of voting, ending her eleven-year tenure as Prime Minister. Though she remains a domestically polarising figure, historians and political scientists generally rank Thatcher as an above-average Prime Minister. Biographer John Campbell reports that in July 1978 when asked by a Labour MP in Commons what she meant by socialism: