Calling him "Maun Modi", the Congress on Wednesday questioned Prime Minister Narendra Modi's "conspiratorial" silence on the Lalit Modi controversy."The prime minister is doing 'Maun Yoga' and his new name should be 'Maun Modi'," Congress spokesperson Randeep Singh Surjewala said at a press conference here.During his 2014 election campaign, Modi had repeatedly referred to former prime minister Manmohan Singh as "Maunmohan Singh"."The prime minister has a conspiratorial silence. It can only come from a person who is either guilty himself or has something to hide," Surjewala said."He (the prime minister) has been quiet for four days now. There is no tweet from him," Surjewala said.The party is demanding the resignation of External Affairs Sushma Swaraj over her assistance to Lalit Modi to get travel documents from the British authorities after his Indian passport was revoked.