趙桓(宋(song)欽(qin)宗(zong)(zong)(zong))即位后(hou)(hou),升李(li)(li)(li)綱(gang)(gang)為尚(shang)書(shu)右(you)丞,就(jiu)(jiu)任(ren)親征行營(ying)使(shi),負責(ze)開封(feng)(feng)(feng)的(de)(de)防御。李(li)(li)(li)綱(gang)(gang)率領(ling)(ling)開封(feng)(feng)(feng)軍(jun)(jun)民及(ji)時完(wan)成(cheng)防御部署,親自登城督戰(zhan),擊(ji)退金(jin)兵(bing)(bing)。金(jin)帥完(wan)顏(yan)宗(zong)(zong)(zong)望見(jian)開封(feng)(feng)(feng)難以(yi)強攻(gong)(gong),轉而施行誘降(jiang)(jiang)之(zhi)計,宋(song)廷(ting)彌漫了屈辱投(tou)降(jiang)(jiang)的(de)(de)氣氛。李(li)(li)(li)綱(gang)(gang)因堅決反(fan)對(dui)向金(jin)割(ge)地求和,被(bei)宋(song)欽(qin)宗(zong)(zong)(zong)罷官。由于(yu)開封(feng)(feng)(feng)軍(jun)(jun)民憤怒示(shi)威,迫(po)(po)使(shi)宋(song)欽(qin)宗(zong)(zong)(zong)收回(hui)成(cheng)命,李(li)(li)(li)綱(gang)(gang)才又被(bei)起用。完(wan)顏(yan)宗(zong)(zong)(zong)望因無(wu)力(li)攻(gong)(gong)破(po)開封(feng)(feng)(feng),在宋(song)廷(ting)答應割(ge)讓河北三鎮(zhen)之(zhi)后(hou)(hou),遂于(yu)靖康(kang)(kang)元(yuan)年(nian)(nian)(nian)(1126年(nian)(nian)(nian))二月(yue)撤(che)兵(bing)(bing)。開封(feng)(feng)(feng)守衛戰(zhan)在李(li)(li)(li)綱(gang)(gang)組織下獲得勝利。金(jin)兵(bing)(bing)撤(che)離之(zhi)后(hou)(hou),李(li)(li)(li)綱(gang)(gang)即遭到宋(song)廷(ting)投(tou)降(jiang)(jiang)派的(de)(de)排斥和誣陷。靖康(kang)(kang)元(yuan)年(nian)(nian)(nian)(1126年(nian)(nian)(nian))五(wu)月(yue),宋(song)廷(ting)強令(ling)李(li)(li)(li)綱(gang)(gang)出任(ren)河東(dong)(dong)、河北宣(xuan)撫(fu)使(shi),驅趕他(ta)(ta)出朝。李(li)(li)(li)綱(gang)(gang)就(jiu)(jiu)任(ren)后(hou)(hou),宋(song)廷(ting)又事(shi)事(shi)加以(yi)限制(zhi),使(shi)宣(xuan)撫(fu)使(shi)徒具空名,無(wu)節制(zhi)軍(jun)(jun)隊之(zhi)權。李(li)(li)(li)綱(gang)(gang)被(bei)迫(po)(po)于(yu)靖康(kang)(kang)元(yuan)年(nian)(nian)(nian)(1126年(nian)(nian)(nian))九月(yue)辭職,旋又被(bei)加上“專主戰(zhan)議(yi),喪師費財”的(de)(de)罪名,先責(ze)建(jian)昌(chang)軍(jun)(jun)(今(jin)江西(xi)南(nan)(nan)城)安置,再謫夔州(今(jin)重慶奉(feng)節白(bai)帝城)。李(li)(li)(li)綱(gang)(gang)被(bei)貶(bian)不(bu)久,金(jin)兵(bing)(bing)再次兩路南(nan)(nan)下圍攻(gong)(gong)開封(feng)(feng)(feng)。宋(song)欽(qin)宗(zong)(zong)(zong)在被(bei)俘前夕(xi)又想(xiang)起用李(li)(li)(li)綱(gang)(gang),任(ren)命他(ta)(ta)為資政殿大(da)學(xue)士、領(ling)(ling)開封(feng)(feng)(feng)府事(shi),但已(yi)無(wu)濟于(yu)事(shi)。南(nan)(nan)宋(song)建(jian)立后(hou)(hou),他(ta)(ta)主張堅決抗(kang)金(jin)及(ji)反(fan)對(dui)投(tou)降(jiang)(jiang)活動,卻為宋(song)高(gao)宗(zong)(zong)(zong)及(ji)汪(wang)伯彥、黃(huang)潛善(shan)所不(bu)容。因此(ci),他(ta)(ta)們又設法驅逐李(li)(li)(li)綱(gang)(gang)。首先,調(diao)李(li)(li)(li)綱(gang)(gang)任(ren)尚(shang)書(shu)左仆射兼(jian)門下侍(shi)郎(lang)(左相),另委黃(huang)潛善(shan)接任(ren)右(you)仆射兼(jian)中書(shu)侍(shi)郎(lang),以(yi)牽制(zhi)李(li)(li)(li)綱(gang)(gang)。接著,又罷免(mian)張所、傅亮(liang),撤(che)銷河北招撫(fu)司及(ji)河東(dong)(dong)經制(zhi)司,蓄意破(po)壞李(li)(li)(li)綱(gang)(gang)的(de)(de)抗(kang)金(jin)部署,迫(po)(po)使(shi)李(li)(li)(li)綱(gang)(gang)辭職。李(li)(li)(li)綱(gang)(gang)主政僅七十五(wu)天,建(jian)炎元(yuan)年(nian)(nian)(nian)(1127年(nian)(nian)(nian))八月(yue)十八日便遭罷相,為觀文(wen)殿大(da)學(xue)士,提舉(ju)杭州洞霄宮。一生為國(guo),卻不(bu)得愿。