A member of parliament (MP) is the representative of the people who live in their constituency. In many countries with bicameral parliaments, this term implies members of the lower house, as upper houses often have a different title. Member of Congress or Deputy is an equivalent term in other jurisdictions. Parliamentarian is also sometimes used to describe members of parliament, but the term may also be used to refer to unelected government officials with specific roles in the parliament, such as the Senate Parliamentarian in the United States, or to imply the characteristic of performing the duties of a member of a legislature, e.g. "The two party leaders often disagreed on issues, but both were excellent parliamentarians and cooperated to get many good things done."
There is a reason why the tributes today to Sir David Amess from all parts of the political system were so fulsome - he was..