Mumbai Congress president Milind Deora stepped down from his post on Sunday, saying that he would contribute to build the party at national level. A statement has been issued by his office in this regard. "The same has been conveyed to All India Congress Committee general secretaries Mallikarjun Kharge and K C Venugopal," the statement said. Derora, son of late former union minister Murli Deora, suggested to formulate collective leadership comprising three senior party leaders to oversee the city unit.