 Macphail served as the first chairman of the Ontario CCF from 1932 until 1934.As a UFO Member of Parliament (MP) in the Canadian House of Commons, she was forced to resign from the CCF after the UFO withdrew from the party after alleging communist influence in it.Consequently, the UFO's two candidates in the 1934 provincial election, including longtime MLA Farquhar Oliver, ran under the UFO banner rather than with the CCF.