He was a Minister in the Cabinet of Singapore and a member of parliament for Potong Pasir from 1979 to 1984. He was key in developing Singapore's infrastructural and financial framework, including the Mass Rapid Transit (MRT) system, Singapore Changi Airport and public housing. In 1984, during his term as Minister for Health, to address issues raised by a greying population, he made the controversial proposal to raise the age for the withdrawal of Central Provident Fund (CPF) savings from 55 to 60 years in order that Singaporeans might have more money to live on in their old age.