趙桓(宋(song)(song)(song)(song)欽宗(zong)(zong))即(ji)位后,升李(li)(li)綱(gang)(gang)(gang)為(wei)尚書(shu)右丞,就(jiu)任(ren)(ren)親征行營(ying)使,負(fu)責開(kai)封(feng)的防(fang)御(yu)(yu)。李(li)(li)綱(gang)(gang)(gang)率(lv)領開(kai)封(feng)軍民及時(shi)完成防(fang)御(yu)(yu)部署,親自登城(cheng)督戰(zhan),擊(ji)退金(jin)(jin)(jin)(jin)兵。金(jin)(jin)(jin)(jin)帥(shuai)完顏(yan)宗(zong)(zong)望(wang)見開(kai)封(feng)難以(yi)強攻(gong),轉而(er)施(shi)行誘降之(zhi)計,宋(song)(song)(song)(song)廷彌(mi)漫了屈辱投降的氣氛。李(li)(li)綱(gang)(gang)(gang)因堅(jian)決反對向金(jin)(jin)(jin)(jin)割地求和,被(bei)宋(song)(song)(song)(song)欽宗(zong)(zong)罷官。由于開(kai)封(feng)軍民憤(fen)怒示(shi)威,迫(po)使宋(song)(song)(song)(song)欽宗(zong)(zong)收回成命,李(li)(li)綱(gang)(gang)(gang)才(cai)又被(bei)起用。完顏(yan)宗(zong)(zong)望(wang)因無力攻(gong)破開(kai)封(feng),在宋(song)(song)(song)(song)廷答應(ying)割讓河北(bei)三鎮之(zhi)后,遂于靖(jing)康元(yuan)(yuan)年(nian)(nian)(nian)(1126年(nian)(nian)(nian))二月撤兵。開(kai)封(feng)守(shou)衛戰(zhan)在李(li)(li)綱(gang)(gang)(gang)組(zu)織下獲得勝利(li)。金(jin)(jin)(jin)(jin)兵撤離之(zhi)后,李(li)(li)綱(gang)(gang)(gang)即(ji)遭到宋(song)(song)(song)(song)廷投降派的排斥和誣陷。靖(jing)康元(yuan)(yuan)年(nian)(nian)(nian)(1126年(nian)(nian)(nian))五(wu)月,宋(song)(song)(song)(song)廷強令(ling)李(li)(li)綱(gang)(gang)(gang)出任(ren)(ren)河東、河北(bei)宣撫(fu)使,驅(qu)趕他出朝(chao)。李(li)(li)綱(gang)(gang)(gang)就(jiu)任(ren)(ren)后,宋(song)(song)(song)(song)廷又事(shi)事(shi)加以(yi)限制,使宣撫(fu)使徒(tu)具空名,無節制軍隊(dui)之(zhi)權。李(li)(li)綱(gang)(gang)(gang)被(bei)迫(po)于靖(jing)康元(yuan)(yuan)年(nian)(nian)(nian)(1126年(nian)(nian)(nian))九月辭職,旋又被(bei)加上“專主戰(zhan)議,喪師費財”的罪名,先(xian)(xian)責建昌軍(今(jin)(jin)江西(xi)南(nan)城(cheng))安置,再(zai)謫夔州(zhou)(今(jin)(jin)重慶(qing)奉節白帝城(cheng))。李(li)(li)綱(gang)(gang)(gang)被(bei)貶不久,金(jin)(jin)(jin)(jin)兵再(zai)次兩(liang)路南(nan)下圍攻(gong)開(kai)封(feng)。宋(song)(song)(song)(song)欽宗(zong)(zong)在被(bei)俘(fu)前夕(xi)又想起用李(li)(li)綱(gang)(gang)(gang),任(ren)(ren)命他為(wei)資政(zheng)殿大(da)學士(shi)、領開(kai)封(feng)府事(shi),但(dan)已無濟(ji)于事(shi)。南(nan)宋(song)(song)(song)(song)建立后,他主張(zhang)堅(jian)決抗金(jin)(jin)(jin)(jin)及反對投降活動,卻(que)為(wei)宋(song)(song)(song)(song)高(gao)宗(zong)(zong)及汪伯彥、黃潛善所不容(rong)。因此,他們又設法驅(qu)逐李(li)(li)綱(gang)(gang)(gang)。首(shou)先(xian)(xian),調(diao)李(li)(li)綱(gang)(gang)(gang)任(ren)(ren)尚書(shu)左仆射兼門下侍(shi)郎(左相),另委(wei)黃潛善接任(ren)(ren)右仆射兼中書(shu)侍(shi)郎,以(yi)牽制李(li)(li)綱(gang)(gang)(gang)。接著,又罷免張(zhang)所、傅(fu)亮,撤銷(xiao)河北(bei)招撫(fu)司(si)及河東經制司(si),蓄意破壞李(li)(li)綱(gang)(gang)(gang)的抗金(jin)(jin)(jin)(jin)部署,迫(po)使李(li)(li)綱(gang)(gang)(gang)辭職。李(li)(li)綱(gang)(gang)(gang)主政(zheng)僅七十(shi)五(wu)天,建炎元(yuan)(yuan)年(nian)(nian)(nian)(1127年(nian)(nian)(nian))八月十(shi)八日便(bian)遭罷相,為(wei)觀文殿大(da)學士(shi),提舉杭州(zhou)洞霄宮。一生為(wei)國(guo),卻(que)不得愿。