Congress on Sunday appointed senior leaders Mallikarjun Kharge, Pawan Kumar Bansal, TS Singh Deo, Bhupesh Baghel and Rajeev Shukla as its central observers ahead of the Rajya Sabha polls. Kharge has been appointed observer in Maharashtra, Bansal and Deo in Rajasthan and Baghel and Shukla in Haryana. These leaders will take the responsibility with immediate effect.