In 655, with Emperor Gaozong having lost favor in his wife Empress Wang and greatly favoring his concubine Consort Wu, he wanted to depose Empress Wang and create Consort Wu empress. Almost all high level officials opposed—on the account that Consort Wu had previously been a concubine of Emperor Taizong and therefore having her as a wife would be considered incest, and on the account that Empress Wang was from an honored clan while Consort Wu, while herself from a noble family, was not as highly born—with the conspicuous exceptions of Li Ji, Zhangsun Wuji, and Yu Zhining, each of whom was silent, although Zhangsun and Yu showed their disapproval. The opposition from Chu Shuiliang was particularly fervent. However, when Emperor Gaozong summoned Li Ji to ask his opinion, Li Ji responded, "This is your family matter, Your Imperial Majesty. Why ask anyone else?" Emperor Gaozong therefore deposed Empress Wang and her ally Consort Xiao to commoner rank and created Consort Wu empress instead, having Li Ji serve as the ceremonial emissary. (Later, at Empress Wu's request, Emperor Gaozong further executed the former Empress Wang and Consort Xiao.) Empress Wu soon became dominant at court, installing officials who favored her ascension in chancellor posts and carrying out a near complete purge of the officials who opposed her or showed disapproval, even including Zhangsun (who, as Emperor Gaozong's uncle, was a major advocate for his having been made crown prince), but Li Ji, not having opposed her, escaped such actions. (Li Ji was nominally put in charge of the investigation during false accusations against Zhangsun for treason (brought by Empress Wu's associate Xu Jingzong), but it does not appear that he was actually responsible for Zhangsun's demise.) In 663, Li Ji was in charge of the corruption probe against another associate of Empress Wu's, the chancellor Li Yifu, leading to Li Yifu's removal, although, again, Li Ji's own involvement was not clear.