Prime minister leader, the incoming leader will usually be referred as "prime minister-in-waiting". An example or this situation was in 2016 in the United Kingdom when Theresa May was elected leader of the Conservative Party while David Cameron was still prime minister. Ukraine's constitution (1996) lists the powers, functions and duties of the Prime Minister of Ukraine. Most prime ministers in parliamentary systems are not appointed for a specific term in office and in effect may remain in power through a number of elections and parliaments. For example, Margaret Thatcher was only ever appointed prime minister on "one" occasion, in 1979. She
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: