"The nation is looking for a leader in the presentc ircumstances. But where are you, Mr Nawaz Sharif? Why are you silent?" asked Khan, chief of Pakistan Tehreek-i-Insaf.
The cricketer-turned-politician alleged that Sharif was silent on the LoC situation to save his business interests.
Khan said he wants "friendly relations with neighbours but cannot allow anyone to commit aggression".
He was addressing his party workers last night in front of parliament where they are protesting since August to remove Sharif for alleged fraud in polls last year.
India and Pakistan have been trading heavy mortar and gun ire along the international border and LoC since more than a week.