The League for Democratic Rights was formed in 1950 out of a union of the Civil Rights Union, the newly-formed Montreal Civil Liberties Union and a group in Timmins. As was the case with the Association for Civil Liberties, the League for Democratic Rights was an attempt to form a national rights association, but one inclusive of communists. The League for Democratic Rights claimed to have affiliates across the country and received funds from each affiliate and various unions.

According to Ross Lambertson: "The LDR was shunned by the "right wing" civil liberties organizations, but seventeen months later its letterhead claimed twenty-four affiliated branches in Sydney N. S., Québec City, Montréal, Ottawa, Toronto, Hamilton, Niagara Peninsula, London, Windsor, Sault St. Marie, Timmins, Port Arthur, Fort William, Winnipeg, Brandon, Regina, Moose Jaw, Saskatoon, Edmonton, Calgary, Newcastle (Alta), East Coulee (Alta), Lethbridge, and Vancouver. In 1953 it boasted 'branches, committees, or affiliates in 31 centres across the country.' This latter figure may have been somewhat inflated, but an examination of the financial reports of the LDR indicates that the organization expected, and received, regular donations of money from most of the above-mentioned groups, with Montréal and Toronto giving the most, followed by the Vancouver branch. In addition, it received regular infusions of money from a number of radical left-wing groups and unions, such as UJPO, the UE Workers, Mine-Mill, and the United Mine Workers of America In short, the LDR could legitimately claim to be Canada's body national civil liberties organization, although one severely truncated by the absence of certain 'right-wing" organizations such as the ACL or the VCCLU. ... For the most part the LDR concentrated upon three issues: eliminating the Padlock law, opposing certain amendments to the Criminal Code, and the need for a bill of rights." (Lambertson, 320).