▁Kingdom , ▁and ▁on ▁ 2 9 ▁January ▁ 2 0 2 0 ▁by ▁the ▁European ▁Parliament . ▁The ▁UK ▁left ▁the ▁EU ▁on ▁ 3 1 ▁January ▁ 2 0 2 0 ▁at ▁ 2 3 : 0 0 ▁G MT . ▁ ▁Three ▁territ ories ▁of ▁EU ▁member ▁states ▁have ▁with dra wn : ▁French ▁Al ger ia ▁( in ▁ 1 9 6 2 , ▁upon ▁independence ), ▁Green land ▁( in ▁ 1 9 8 5 , ▁following ▁a ▁refer endum ) ▁and ▁Saint ▁Bar th é le my ▁( in ▁ 2 0 1 2 ), ▁the ▁latter ▁two ▁becoming ▁O verse as ▁Count ries ▁and ▁Territ ories ▁of ▁the ▁European ▁Union . ▁ ▁Background ▁The ▁states ▁who ▁were ▁set ▁to ▁acc ede ▁to ▁the ▁EU ▁in ▁ 2 0 0 4 ▁pushed ▁for ▁an ▁exit ▁right ▁during ▁the ▁ 2 0 0 2 – 2 0 0 3 ▁European ▁Convention . ▁The ▁acc eding ▁states ▁wanted ▁the ▁option ▁to ▁exit ▁the ▁EU ▁in ▁the ▁event ▁that ▁EU ▁membership ▁would ▁advers ely ▁affect ▁them . ▁During ▁negoti ations , ▁eu ros cept ics ▁in ▁states ▁such ▁as ▁the ▁UK ▁and ▁Den mark ▁subsequently ▁pushed ▁for ▁the ▁creation ▁of ▁Article ▁ 5 0 . ▁ ▁Article ▁ 5 0 , ▁which ▁allows ▁a ▁member ▁state ▁to ▁withdraw , ▁was ▁originally ▁draft ed ▁by ▁Scottish ▁cross - ben ch ▁peer ▁and ▁former ▁diplom at ▁Lord ▁K err ▁of ▁Kin lo ch ard , ▁the ▁secretary - general ▁of ▁the ▁European