The source of this term are the United Kingdom general elections that are carried out for the House of Commons.
Due to the spread of this term from the [Mother of Parliaments]?, this term is used in other countries around the world.
It is an old, well-established term that is still in use around the world as a search for ["Mother of Parliaments" on Google] will confirm. It probably needs its own page so I used it here so the basis for such an entry. After all the term "general election" has probably spread from the same source as "parliament" so I thought it would be apt to use it here. Feel free to differ. -- Aristotle