The first prime minister, D.S. Senanayake of the conservative UNP, reacting to the possibilities of losing power to leftist political parties, commenced the task of weakening the leftist parties and their associate organizations. Indian Tamil labour had overwhelmingly supported these organizations. According to opposition parties he was also influenced by segments of the majority Sinhalese population who felt their voting strength was diluted due to Indian Tamils. He introduced the "Ceylon Citizenship Act of 1948", the "Indian-Pakistani Citizenship Act of 1949" and amended the "Parliamentary Elections Act" and disfranchised the Indian Tamils along with many persons of Indian and Pakistani ancestry. As they had no means of electing anyone to the Parliament they ceased to be a concern of parliamentary politicians. The plantation workers were thus forgotten from 1948 to 1964. They were unable to profit by any progressive legislation. The housing, health and education of the plantation workers was neglected. Infant mortality was highest in the country. Although since the introduction of universal franchise in 1931, strong traditions of social welfare in Sri Lanka have given the island very high indicators of physical well-being. Impressive national statistics tended to hide the existence of deprived pockets within the population and the most deprived population group has been the plantation labour, which had been economically, politically and socially deprived.