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.
Deputy Prime Minister of Canada role, few to no research sources exist to provide a complete list of everyone who was ever named as acting prime minister. However, John Diefenbaker's selection of Ellen Fairclough as acting prime minister on February 19 and 20, 1958, is historically noteworthy as Fairclough was the first woman ever designated. Prior to the creation of this position, the position of "Senior Minister" was a ceremonial position used in a similar manner, heading the order of precedence. Upon the absence of the Prime Minister, the Senior Minister would become the Acting Prime Minister. Deputy Prime Minister of Canada The Deputy Prime