Missioners should not be confused with canvassers, as they were expressly prohibited from soliciting votes for an individual candidate. Their purpose was to assist the Agent in collecting subscriptions, gathering intelligence, and in recruiting new members.

They were employed centrally (presumably through Area Offices), and their functions were set out in a memorandum dated 31 July 1947, from the Chief Organisation Officer: 'Missioners are only to be employed in house-to-house visiting, and their tasks may be defined as follows (in order of priority):

A missioners' scheme appears to have been put in place for the duration of every general election campaign, and to assist with specific public opinion surveys.