Islamabad, Aug 14 : Former Pakistan Prime Minister and PTI chief Imran Khan has warned that the government is about to launch "an unprecedented crackdown campaign" against media houses and journalists supporting him, media reports said. In a series of tweets on Sunday -- a day after he addressed a public rally in Lahore -- Imran Khan expressed fears that if the government succeeded in suppressing journalists who have supported his narrative the country may "be returning to the dark days of dictatorship when there was no independent media & no room for freedom of expression", Samaa TV reported. Khan named about five anchors and columnist Ayaz Amir who, he said, suffered "threats, violent attacks and arrests" for supporting him. "In my mass public campaign across Pakistan from next week, I will take up the issue of media freedom and freedom of expression," he said. "If we allow these terror tactics, designed simply to target PTI and myself, to succeed, then we will be returning to the dark days of dictatorship when there was no independent media & no room for freedom of expression," Khan said, Samaa TV reported. "Haqeeqi Azadi cannot be achieved without a free media & freedom of speech as guaranteed in our Constitution," said the former Prime Minister, whose government saw Pakistan sink on the press freedom index in the three-and-a-half years he was in power. /IANS