 Complete the following phrase:  In November 2004, the partys Propaganda Department banned Li from being published in the media. His books on Mao were censored and banned in Mainland China. In 2006, he was a lead signatory to an open letter condemning the states closure of the investigative newspaper Freezing Point. Ahead of the 17th Communist Party Congress in 2007, Li and retired academic Xie Tao published articles calling for the Communist Party to become a European-style socialist party, remarks that were condemned by the party propaganda apparatus. In October 2010, Li was the lead signatory to an open letter to the Standing Committee of the National Peoples Congress, calling for greater press freedom. Before every quinquennial party congress, Li wrote to fellow senior party members, advocating political reform. In 2017, Li failed to attend the 