 With little prospect of help from <unk> arriving , infighting broke out in the Song court between the officials who supported the Jin offer and those who opposed it . Opponents of the treaty like Li Gang ( <unk> ; <unk> – 1140 ) rallied around the proposal of remaining in defensive positions until reinforcements arrived and Jurchen supplies ran out . They <unk> an ambush against the Jin that was carried out at night , and were replaced by officials who supported peace negotiations . The failed attack pushed Qinzong into meeting the Jurchen demands , and his officials convinced him to go through with the deal . The Song recognized Jin control over the three prefectures . The Jurchen army ended the siege in March after 33 days . 
