A Parliamentary Secretary is a member of a Parliament in the Westminster system who assists a more senior minister with his or her duties.
In the parliamentary systems of several Commonwealth countries, such as the United Kingdom, Canada and Australia, it is customary for the prime minister to appoint parliamentary secretaries (in the Legislative Assembly of Ontario, "parliamentary assistants") from his or her political party in parliament to assist cabinet ministers with their work. The role of parliamentary secretaries has varied under different prime ministers. Originally, the post was used as a training ground for future ministers.
In the United Kingdom, Parliamentary Secretary (in full, usually Parliamentary Under-Secretary of State in those departments headed by a Secretary of State) is the third level of government minister, below Minister of State and Secretary of State (or another minister of Secretary of State rank, such as the Chancellor of the Exchequer). Not all departments have all three levels of minister.
A Parliamentary Private Secretary (PPS), on the other hand, is a Member of Parliament who acts as an unpaid assistant to an individual minister, but has no ministerial role, although is expected to support the government at all times.
During Jean Chrétien's term as Prime Minister of Canada, parliamentary secretaries were set to two-year terms and the post was used as a reward for weary backbenchers. Their duty was to answer questions and table reports on behalf of ministers when they were unable to be present in the house.
Chrétien's successor as Canadian Prime Minister, Paul Martin, when sworn-in in 2003, promised a new role for parliamentary secretaries. They would now be sworn into the privy council, giving them access to some secret documents, and allowing them to attend Canadian Cabinet meetings and be assigned specific files by ministers. This replaced the positions of Secretaries of State which had been employed under Chrétien.
In the Irish Free State, the Ministers and Secretaries Act of 1924 created the post of Parliamentary Secretary, originally limited to seven holders. In 1978, the office was superseded in the Republic of Ireland by the office of Minister of State.