The High Court of Australia invalidated the Menzies’ government’s Communist Party Dissolution Act on March 9, 1951.
The bill to ban the party was passed in 1950, the first full year of the Liberal-Country Party government Robert Menzies brought to office in December 1949.
The legislation was ultimately allowed through the Labor-controlled Senate, denying Menzies the opportunity to use the bill as a double dissolution trigger. However, Menzies secured a double dissolution election on April 28, 1951 due to the blocking of the Commonwealth Bank Bill. The government was returned to office with a slightly-reduced majority in the House, but it gained control of the Senate.