But behind the simplicity of the notice is a more complex story — about who gets to set India’s negotiating line on climate change at a time when there is enormous pressure on the country to give up its core positions on the issue.

Last year, the tussle between Environment Minister Jairam Ramesh and the SEPM virtually spilled out into the open with the leak of a letter written by Mr. Saran to the Prime Minister listing his misgivings about the direction the Minister seemed to be heading in. And he was not alone. C. Dasgupta and Prodipto Ghosh — retired officials who have specialised on the subject and who were part of the Indian negotiating team — also questioned the wisdom of some of Mr. Ramesh’s pronouncements, especially on accepting international monitoring and diluting the per capita norm. They only agreed to go to Copenhagen after the Minister reassured them there would be no dilution in India’s stand.

In the aftermath of the summit, the Prime Minister came under pressure to re-evaluate the role of the SEPM with some arguing that the Environment Minister should be given sole authority to decide India’s climate change strategy at the global level.

One of those who wrote to Manmohan Singh asking that Mr. Ramesh be given full charge was N. K. Singh, the Rajya Sabha M.P. Mr. Singh’s letter appreciated Mr. Saran’s negotiating skills but said the absence of symmetry was leading to confusion.

Whatever the trigger, Mr. Saran is the second high-profile climate negotiator to exit the stage after crossing swords with the United States. Last December, the Philippines government sacked its chief negotiator, Bernaditas Castro-Muller, in the run-up to the Copenhagen summit, a move civil society groups said was taken to please Washington.

Sources close to Mr. Saran said his reasons for resigning from the job, which had an open-ended tenure, were personal and had nothing to do with the politics of climate change policy.

Highly placed sources told The Hindu that although the Prime Minister was still to take a final call on the matter, the SEPM would not be replaced and his office will likely be shut down. One of the options is for the Environment Ministry to take full charge of India’s negotiating strategy on climate change. A senior official said Mr. Saran was brought in at a time when the Environment Ministry was headed by less articulate ministers and that with Mr. Ramesh at the helm now there was no need to have a special envoy.

At the same time, the fact that the climate change issue requires inter-agency consultations and has not just technical but political and strategic dimensions means there is a logic to the PMO remaining in overall control. One of the options, therefore, could be for National Security Adviser Shiv Shankar Menon to be tasked with coordination.

Senior officials brushed aside suggestions in a section of the media that protocol issues might have played a role in the SEPM’s departure.

They said the Prime Minister had told Mr. Saran (and his special envoy on Pakistan, Satinder Lambah) last month that they would both have ‘Minister of State’ rank since Mr. Menon, their junior in the Indian Foreign Service, had MoS status as NSA.

As for Mr. Dasgupta and Mr. Ghosh who have sounded a contrarian note to Mr. Ramesh in the past, their services as negotiators will likely not be availed of in the future, officials said.