Chief Minister Arvind Kejriwal said Friday that the central government's approval was not needed for the Delhi assembly to pass a Jan Lokpal bill.In a communication to Lt. Governor Najeeb Jung, Kejriwal urged him not to be swayed by the central government. "You have taken oath to be loyal to the constitution, not any party or the home ministry. Don't let the constitution die," Kejriwal wrote in a three-page letter in Hindi circulated to the media.The letter followed the Solicitor General's reported opinion that the bill cannot be passed in the Delhi assembly without the approval of the central government.