OTTAWA -- The controversy over New Democrat MPs' allegedly improper use of their free parliamentary mailing privileges to blanket 26 ridings with almost 2 million partisan missives has put the spotlight on "franking."

Franking refers to a mark or signature on an envelope signifying that it is to be mailed free of charge.

It's a long-standing privilege enjoyed by members of both houses of Parliament and by all Canadians, intended to ensure postage costs don't inhibit communication between citizens and their government.

Under the Canada Post Corporation Act, regular mail to or from the following is free of charge:

  • the Governor General
  • MPs
  • Senators
  • Speaker of the House of Commons
  • Speaker of the Senate
  • Parliamentary librarian
  • House of Commons ethics commissioner
  • Senate ethics officer

In addition, the act specifies that MPs may send their constituents four unaddressed "mailings of printed matter" -- what the post office calls unaddressed ad mail -- each calendar year, free of charge.

MPs who choose to send more than four unaddressed mass mailings in a year, are given a "deeply discounted rate," according to Canada Post.

Last year, the post office says it delivered some 6 million franked letters and almost 132 million pieces of unaddressed ad mail.

The federal government provides Canada Post with an annual subsidy of $22 million to help cover the cost of franked parliamentary mail and the cost of free mailings of materials to the blind.