Flag Debate, the debate over the proposed new Canadian flag which opened in the House of Commons 15 June 1964 and ended by closure 15 December 1964. Canada's official flag from 1867 had been Britain's Union Flag, although the Red Ensign with the Canadian badge was regularly flown for qualified purposes. In 1925 Prime Minister Mackenzie King appointed an armed services committee to investigate possible designs, but it did not report. In 1946 a committee of both Senate and Commons presented a design with the Red Ensign charged with a golden maple leaf but it was not adopted. The issue was raised again by Lester Pearson, as leader of the Opposition in 1960 and as prime minister in 1963. John Matheson MP sought strict adherence to the colours, red and white, and the maple leaf emblem authorized by George V on 21 November 1921 as advocated by A. Fortescue Duguid. Alan B. Beddoe added two blue bars to what became known as the "Pearson pennant." This proposal for design, three maple leaves on a white centre square with blue bars on each side, was introduced to Parliament in June 1964.

The ensuing controversy raged not over whether there should be a new flag, but on its design. The French Canadian members followed with keen interest a debate wherein feelings ran high among many English-speaking Canadians. John Diefenbaker demanded that the flag honour the "founding races," with the Union Jack in the canton of honour. Pearson insisted on a design denoting allegiance to Canada devoid of colonial association. After prolonged, rancorous debate the issue was referred to a 15-member all-party committee which recommended a design inspired by the Royal Military College flag theme, red-white-red, but with one red maple leaf in a white squared centre. Debate in the House continued until Léon Balcer, a prominent Conservative MP from Québec, invited the Liberals to invoke closure, which would limit speeches to 20 minutes and force a vote. After some 250 speeches, a vote was taken 15 December 1964 at 2:00 a.m. and the committee's recommendation was accepted 163 to 78. Senate approval followed on Dec 17. The royal proclamation was signed by Her Majesty 28 January 1965 and the national flag was officially unfurled 15 February 1965.

See also Heraldry; Emblems of Canada.