趙桓(宋(song)(song)(song)(song)欽(qin)宗(zong)(zong)(zong))即位后,升李(li)(li)(li)(li)綱(gang)(gang)(gang)(gang)為(wei)尚書(shu)(shu)右(you)丞,就任(ren)親征行(xing)(xing)營(ying)使(shi)(shi),負責(ze)開(kai)(kai)封(feng)(feng)的(de)防御。李(li)(li)(li)(li)綱(gang)(gang)(gang)(gang)率領開(kai)(kai)封(feng)(feng)軍民(min)及(ji)(ji)時完(wan)成(cheng)防御部(bu)署(shu),親自登城(cheng)(cheng)督戰(zhan)(zhan),擊退(tui)金(jin)兵(bing)(bing)。金(jin)帥完(wan)顏宗(zong)(zong)(zong)望(wang)見開(kai)(kai)封(feng)(feng)難以(yi)強攻(gong),轉而施行(xing)(xing)誘降之(zhi)計,宋(song)(song)(song)(song)廷(ting)彌漫(man)了(le)屈辱投降的(de)氣氛。李(li)(li)(li)(li)綱(gang)(gang)(gang)(gang)因堅決反對向金(jin)割地求和,被(bei)(bei)宋(song)(song)(song)(song)欽(qin)宗(zong)(zong)(zong)罷官。由(you)于開(kai)(kai)封(feng)(feng)軍民(min)憤怒(nu)示威(wei),迫(po)(po)使(shi)(shi)宋(song)(song)(song)(song)欽(qin)宗(zong)(zong)(zong)收回成(cheng)命,李(li)(li)(li)(li)綱(gang)(gang)(gang)(gang)才又(you)被(bei)(bei)起用(yong)(yong)。完(wan)顏宗(zong)(zong)(zong)望(wang)因無(wu)力(li)攻(gong)破(po)開(kai)(kai)封(feng)(feng),在宋(song)(song)(song)(song)廷(ting)答(da)應割讓河(he)北(bei)三鎮之(zhi)后,遂于靖(jing)康(kang)(kang)(kang)元(yuan)年(nian)(nian)(1126年(nian)(nian))二月(yue)(yue)撤(che)兵(bing)(bing)。開(kai)(kai)封(feng)(feng)守衛戰(zhan)(zhan)在李(li)(li)(li)(li)綱(gang)(gang)(gang)(gang)組織下獲得勝(sheng)利。金(jin)兵(bing)(bing)撤(che)離之(zhi)后,李(li)(li)(li)(li)綱(gang)(gang)(gang)(gang)即遭到宋(song)(song)(song)(song)廷(ting)投降派的(de)排(pai)斥和誣陷。靖(jing)康(kang)(kang)(kang)元(yuan)年(nian)(nian)(1126年(nian)(nian))五月(yue)(yue),宋(song)(song)(song)(song)廷(ting)強令李(li)(li)(li)(li)綱(gang)(gang)(gang)(gang)出任(ren)河(he)東(dong)、河(he)北(bei)宣撫(fu)使(shi)(shi),驅(qu)趕他(ta)出朝。李(li)(li)(li)(li)綱(gang)(gang)(gang)(gang)就任(ren)后,宋(song)(song)(song)(song)廷(ting)又(you)事(shi)事(shi)加以(yi)限制(zhi)(zhi)(zhi),使(shi)(shi)宣撫(fu)使(shi)(shi)徒具空名,無(wu)節(jie)(jie)制(zhi)(zhi)(zhi)軍隊之(zhi)權。李(li)(li)(li)(li)綱(gang)(gang)(gang)(gang)被(bei)(bei)迫(po)(po)于靖(jing)康(kang)(kang)(kang)元(yuan)年(nian)(nian)(1126年(nian)(nian))九月(yue)(yue)辭職,旋(xuan)又(you)被(bei)(bei)加上“專主戰(zhan)(zhan)議,喪師費財”的(de)罪名,先責(ze)建昌(chang)軍(今江西南(nan)(nan)城(cheng)(cheng))安置,再謫夔州(今重慶奉(feng)節(jie)(jie)白帝城(cheng)(cheng))。李(li)(li)(li)(li)綱(gang)(gang)(gang)(gang)被(bei)(bei)貶(bian)不(bu)久,金(jin)兵(bing)(bing)再次兩路(lu)南(nan)(nan)下圍攻(gong)開(kai)(kai)封(feng)(feng)。宋(song)(song)(song)(song)欽(qin)宗(zong)(zong)(zong)在被(bei)(bei)俘前(qian)夕(xi)又(you)想起用(yong)(yong)李(li)(li)(li)(li)綱(gang)(gang)(gang)(gang),任(ren)命他(ta)為(wei)資政殿大學士(shi)、領開(kai)(kai)封(feng)(feng)府事(shi),但已無(wu)濟于事(shi)。南(nan)(nan)宋(song)(song)(song)(song)建立后,他(ta)主張堅決抗金(jin)及(ji)(ji)反對投降活(huo)動,卻為(wei)宋(song)(song)(song)(song)高宗(zong)(zong)(zong)及(ji)(ji)汪伯彥、黃(huang)潛(qian)(qian)善所(suo)不(bu)容。因此,他(ta)們又(you)設法驅(qu)逐(zhu)李(li)(li)(li)(li)綱(gang)(gang)(gang)(gang)。首先,調李(li)(li)(li)(li)綱(gang)(gang)(gang)(gang)任(ren)尚書(shu)(shu)左(zuo)仆(pu)射(she)兼(jian)門(men)下侍郎(左(zuo)相),另委黃(huang)潛(qian)(qian)善接任(ren)右(you)仆(pu)射(she)兼(jian)中書(shu)(shu)侍郎,以(yi)牽制(zhi)(zhi)(zhi)李(li)(li)(li)(li)綱(gang)(gang)(gang)(gang)。接著,又(you)罷免(mian)張所(suo)、傅亮,撤(che)銷河(he)北(bei)招撫(fu)司及(ji)(ji)河(he)東(dong)經制(zhi)(zhi)(zhi)司,蓄意破(po)壞李(li)(li)(li)(li)綱(gang)(gang)(gang)(gang)的(de)抗金(jin)部(bu)署(shu),迫(po)(po)使(shi)(shi)李(li)(li)(li)(li)綱(gang)(gang)(gang)(gang)辭職。李(li)(li)(li)(li)綱(gang)(gang)(gang)(gang)主政僅(jin)七十(shi)五天,建炎(yan)元(yuan)年(nian)(nian)(1127年(nian)(nian))八月(yue)(yue)十(shi)八日便遭罷相,為(wei)觀文殿大學士(shi),提(ti)舉杭州洞霄宮。一生為(wei)國,卻不(bu)得愿(yuan)。