On moving to Leeds in 1976, Parkin discovered the Ecology Party (as the UK Green Party was then known). She stood (unsuccessfully) against Keith Joseph in the 1979 general election and in several local elections. When her husband's work as a cancer epidemiologist took the family to live in Lyon France, she became involved with the international growth of green politics. This including leading on the establishment of the Coordination of (European) Green Parties (a grouping now known as the European Green Party for which she acted as Co-secretary and Spokesperson until 1991. With activists in other European Green Parties she provided support for green-oriented parties around the world, including dissident movements in east Europe.