High Quality Content by WIKIPEDIA articles! In Canada, the Office of the Prime Minister (PMO), located in the Langevin Block, on Parliament Hill, in Ottawa, is one of the most powerful parts of the government. It is made up of the prime minister and his or her top political staff, who are charged with advising the prime minister on decisions, making the office a wholly political body. It should, however, not be confused with the Privy Council Office (PCO).