Ranvijay Singh, a resident of Sultanpur in UP and an activist of Samajwadi Party student wing Chaatra Sabha, sprinkled petrol on his body during the protest at Jantar Mantar and set himself afire at around 12:50 pm, a senior police official said.
He was rushed to Ram Manohar Lohia Hospital, where his condition is stated to be critical.
Sanjay Lal, president of the student wing, said Singh was emotionally charged and he had a letter in his pocket which read: "UP kay Loktantra ki hatya ho rahi hai. Usko bardasht nahi kiya jayega (Democracy is being murdered in UP. We won't tolerate this)".