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 to then, it was the "entire" government that made the request. Similarly, though the modern 1937 Irish constitution grants to the Taoiseach the right to make the request, the earlier 1922 Irish Free State Constitution vested the power in the "Executive Council" (the then name for the Irish cabinet). In Australia, the Prime Minister is expected to step down if s/he loses the majority support of his/her party under a spill motion as have many such as Tony Abbott, Julia Gillard, Kevin Rudd and Malcolm Turnbull. In the Russian constitution the prime minister is actually titled "Chairman of the government"