The letter to Kovind was written by Manmohan Singh and senior Congress leaders A K Antony, Ghulam Nabi Azad, Ahmed Patel, P Chidambaram, Ashok Gehlot, Mallikarjun Kharge, Karan Singh, Ambika Soni, Kamal Nath, Anand Sharma, Motilal Vora, Digvijay Singh and Mukul Wasnik.