 After losing her seat in 1988, MacDonald quit politics and devoted her time to international humanitarian work.She served as Chair of the Board of Canada's International Development Research Centre from 1992 to 1997, and was also president of the World Federalist Movement-Canada.In 2003, she briefly re-entered the political scene to oppose the merger of the Progressive Conservative Party of Canada and the Canadian Alliance, but was unable to prevent the folding of the PCs into the new Conservative Party of Canada.