The tussle between the Arvind Kejriwal-led Delhi government and Lt. Governor Najeeb Jung escalated on Monday when bureaucrat Rajendra Kumar was made principal secretary (services), replacing Anindo Majumdar.Earlier, Majumdar, who issued the order posting Shakuntala Gamlin as acting chief secretary, was barred from entering his office at the Delhi Secretariat."Kumar has been given charge of the Principal Secretary (Services) of the government of Delhi," said an official of the Delhi government.Reacting to this move of the Delhi government Lt. Governor Jung wrote to the chief minister. Deputy Chief Minister Manish Sisodia said that he had received the letter."Letter received from Hon. LG at 14.35," Sisodia tweeted.However, the contents of the letter have not been revealed.The tussle had erupted on May 15 over the appointment of Gamlin as the chief secretary in-charge, who the chief minister accused of lobbying for power distribution companies.