Raising the issue during Zero Hour, P Rajeeve said the HRD Ministry's decision to replace German with Sanskrit in KVs in the middle of the session is "totally against the interest of the students".
"This unilateral decision of the government is totally condemnable," he said.
After replacing German with Sanskrit as third language from Classes VI to VIII, Kendriya Vidyalaya Sangathan (KVS) has decided to revive a policy of teaching Sanskrit in classes XI and XII.
In a communication sent to all Kendriya Vidyalayas, the KVS asked them to hire teachers on contract basis for teaching Sanskrit.
He said there are various regional languages in the country and dubbed the government's decision as "against federal spirit and Constitution".
In the affidavit to the Supreme Court on Monday, the Centre said Sanskrit would be the third language in classes VI to VIII in the KVs.