Vaibhav Singh was shot late last night by motorcycle-borne assailants in Nagbaba lane near Ramlila Maidan when he was on his way to home, police said.
The locals rushed him to the district hospital from where he was referred to Lucknow hospital for treatment, they said.
Singh is said to be a close aide of state's agriculture minister, Vinod Kumar Singh alias Pandit Singh.
SP Sudhir Kumar Singh has transferred a Circle Officer following the incident.