A 29 October 1964 US Embassy cable cited an informed source from the Indian Ministry of External Affairs as saying that "pressures within GOI [Government of India] for India to develop its own bomb were building up" and that "Bhabha was the leading advocate for this group and he was actively campaigning to go down nuclear the road". A six-hour cabinet discussion of nuclear policy had culminated in the Minister of External Affairs Swaran Singh and the influential Minister of Railways S. K. Patil supporting Bhabha, who was attending as an observer, in his proposal for a nuclear weapon-building program. Only two cabinet ministers were against. Prime Minister Lal Bahadur Shastri, Nehru's successor, authorized Bhabha to "come up with estimate of what was involved in India's attempting an underground 'explosion'."