Thampu has been quite vocal in his allegations about the college being subjected to a "harassment" by certain alumni and teachers.
His 8-year tenure as principal of the college, full of controversies with repeated demands for his removal, ends in February 2016.
"Some of my friends have advised me to sit my term out in taciturnity and to exit, awash in goodwill. I must tell them that is not an option for me...The time has come for us to say no, I will not take it anymore, and I am doing that," he said on his Facebook page.
"As soon one controversy lost its sheen, a new one was improvised. It was a collaborative enterprise between a few depraved elements among the alumni to fleeting, mutual benefit," he said.
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The principal has also asserted that those leveling allegations should be held accountable.
"Those who claim the right to make a song and dance in the public space must be held accountable. They must answer. This one-way traffic of aggression against those presumed unequals must stop.
Last week, prominent alumni including Arjuna awardee Raja Randhir Singh, former Congress MP Sandip Dikshit, BJD MP Kalikesh Narayan Singh Deo and Congress leader Sharmishtha Mukherjee, had come out against Thampu's move to push for amendment to the college's 102-year-old constitution for empowering the principal and the Church of North India (CNI).
Former test cricketer and an alumnus Kirti Azad had described the present situation at his alma mater as "disgusting" and said the issue will be raised in Parliament by the MPs who are alumni of the college.