The Delhi High Court yesterday issued show-cause notices to the Centre, Delhi Electricity Supply Undertaking (Desu), the Delhi municipal corporation and Lt-Governor Tejendra Khanna on the worsening power situation in Delhi. Issuing the notice, Justice C M Nayar directed the four respondents to file replies by April 21, the next date of hearing in the case. The notices were issued following a public interest petition by Common Cause, which was represented in court by H D Shourie.