In 1919, the city of Winnipeg was shaken by a General Strike which pitted unionized and non-unionized workers against the city's employers. The strike was suppressed by force, but labour radicalism within the city was greatly increased. There were increased calls for labour unity in the city. For the 1920 provincial election, the SPC, SDP and reformist labour parties forged an electoral alliance to contest Winnipeg's ten seats (which were determined by a single transferable ballot). The labour list received more votes than any other party, and elected four candidates to the Legislature. Armstrong was elected, along with three candidates from the other parties.