Parliamentary Private Secretary to the Prime Minister Bonar Law's Parliamentary Private Secretary, J.C.C. Davidson acted in effect as his Chief of Staff. Margaret Thatcher's downfall from the Conservative Party leadership in 1990 is attributed by many to the actions of her Parliamentary Private Secretary, Peter Morrison, in failing accurately to count votes amongst Conservative backbenchers. Some Parliamentary Private Secretaries to the Prime Minister go on to hold higher office; Lord Dunglass served as Parliamentary Private Secretary under Neville Chamberlain and later went on to serve as Prime Minister in his own right. There can be multiple Parliamentary Private Secretaries to the Prime Minister at a given time.
Prime minister powers (known as the royal prerogative) that are constitutionally vested in the crown and may be exercised without the approval of parliament. As well as being head of government, a prime minister may have other roles or posts—the Prime Minister of the United Kingdom, for example, is also First Lord of the Treasury and Minister for the Civil Service. Prime ministers may take other ministerial posts. For example, during the Second World War, Winston Churchill was also Minister of Defence (although there was then no Ministry of Defence) and in the current cabinet of Israel, Benjamin Netanyahu also serves as