Excerpt
Only a few sitting Members of Parliament are directly involved with executive government. Most MPs are backbenchers, so-called because they inhabit the rear seats in the parliament (the ‘frontbenches’ are only occupied by ministers and shadow ministers). Backbenchers might be junior MPs, relatively inexperienced and ‘learning the ropes’ of parliament.
They might be former ministers or prime ministers who have resigned, lost leadership challenges or been demoted from the cabinet. Or they might be unwilling or unsuited for a ministerial post. Nevertheless, they have a number of important responsibilities in the parliament, including voting on bills, delivering speeches, asking questions during question time and representing the interests and welfare of their electorate.
SOURCE: lawgovpol.com