Shyam Saran, the prime minister's envoy on climate change and former foreign secretary, will demit office in March.
Saran recently lost out to his friend and colleague, Shiv Shankar Menon, in the race to become National Security Advisor. Saran and Menon were both shortlisted for the post of NSA, but Menon got nominated to the prestigious post after many rounds
of talks within the establishment.
Sources said Saran is quitting due to many reasons, one of which includes his ongoing tussle with Environment Minister Jairam Ramesh, and also over the issue of his seniority to Menon.
It is believed that if Saran had become NSA, he would have adopted a more stringent line on China and Pakistan.