Rotblat retired from St Bartholomew's in 1976. In 1975 and 1976, he was Montague Visiting Professor of International Relations at the University of Edinburgh. He believed that scientists have an individual moral responsibility and, just as the Hippocratic Oath provides a code of conduct for physicians, he thought that scientists should have their own code of moral conduct, a Hippocratic Oath for scientists. During his tenure as president of the Pugwash conferences, Rotblat nominated Israeli nuclear technician Mordechai Vanunu for the Nobel Peace Prize every year from 1988 to 2004. Vanunu had disclosed the extent of Israel's nuclear weapons programme and consequently spent 18 years in prison, including more than 11 years in solitary confinement.