 She then joined the Women's Social and Political Union and founded a branch in Dunfermline in 1906. and won support from socialist leaders and Labour's Keir Hardie.In 1907 a row between the membership and the Pankhursts led to a split in the WSPU and as a result the more democratic Women's Freedom League was formed and Munro was elected to be the Secretary of the WFL Scottish Council.She was briefly imprisoned in 1908 for her protesting, and participated in the protests around the 1911 Census, which the suffragettes boycotted.