 That same year, the Comintern in Moscow abandoned its Third Period strategy, which entailed the creation of the Workers' Unity League and similar militant trade union organizations in other countries with the goal of building a radical labour movement separate from mainstream labour organizations.Under the new Popular Front strategy, Communists joined established unions and helped to build the Congress of Industrial Organizations.Moreover, Communist priorities shifted from the industrial to the political arena, where they fielded candidates and supported Cooperative Commonwealth Federation candidates, while others joined the Mackenzie-Papineau Battalion to fight Franco's fascists in the Spanish Civil War.