New Delhi:  PK Sinha, one of the most senior bureaucrats in the Narendra Modi-led government, has resigned on personal grounds, sources claimed on March 16.  A 1977-batch IAS officer of Uttar Pradesh cadre, Sinha was serving as the Principal Advisor to Prime Minister Modi since September 2019. Before assuming the role, he had served as the Cabinet Secretary for four years. Political and bureaucratic circles are wondering this latest development. More news will follow.