 During his time as High Commissioner, Tupper vigorously defended Canada's rights.Although he was not a full plenipotentiary, he represented Canada at a Paris conference in 1883, where he openly disagreed with the British delegation; and in 1884 he was allowed to conduct negotiations for a Canadian commercial treaty with Spain.Tupper was concerned with promoting immigration to Canada and made several tours of various countries in Europe to encourage their citizens to move to Canada.