during the second world war, constantine worked for the ministry of labour and national service as a welfare officer responsible for west indians employed in english factories. in 1943, the manager of a london hotel refused to accommodate constantine and his family on the grounds of their race; constantine successfully sued the hotel company. commentators recognise the case as a milestone in british racial equality. constantine qualified as a barrister in 1954, while also establishing himself as a journalist and broadcaster. he returned to trinidad in 1954, entered politics and became a founding member of the people's national movement, subsequently entering the trinidad government as minister of communications. from 1961 to 1964, he served as trinidad's high commissioner to the united kingdom and, controversially, became involved in issues relating to racial discrimination, including the bristol bus boycott. in his final years, he served on the race relations board, the sports council and the board of governors of the bbc. failing health reduced his effectiveness in some of these roles, and he faced criticism for becoming a part of the british establishment. he died of a heart attack on 1 july 1971, aged 69.