In 1992 Giordano became a national leader of PRC and, in 1996, he was elected for the first time at the Italian Chamber of Deputies. His seat was confirmed in the 2001 and 2006 elections.
President of PRC's group of deputies from October 1998, he was named vice-secretary of the party in 2001 by Fausto Bertinotti. After the latter's election as President of the Italian Chamber of Deputies, Giordano became national secretary of PRC on 7 May 2006.[1]