 During his college life, Mohan Singh was president of the Allahabad University Students' Union during 1968–69 and was largely inspired by the father of the Indian socialist movement Raj Narain and Dr. Ram Manohar Lohia and later with Madhu Limaye.After college, he was detained for 20 months during an emergency for taking part in Raj Narain and Jayaprakash Narayan's movement.He was also imprisoned several times while taking part in student protests in 1966, once for occupying Anand Bhavan, Allahabad, and also in an agitation launched by the Socialist Party on the language issue.