▁the ▁treat ies ' ▁application ▁in ▁said ▁state ▁is ▁not ▁dependent ▁on ▁any ▁agreement ▁being ▁reached ▁( it ▁would ▁occur ▁after ▁two ▁years ▁regardless ). ▁In ▁other ▁words , ▁the ▁European ▁Union ▁can ▁not ▁block ▁a ▁member ▁state ▁from ▁leaving . ▁ ▁If ▁negoti ations ▁do ▁not ▁result ▁in ▁a ▁rat ified ▁agreement , ▁the ▁se ced ing ▁country ▁leaves ▁without ▁an ▁agreement , ▁and ▁the ▁EU ▁Tre aties ▁shall ▁ce ase ▁to ▁apply ▁to ▁the ▁se ced ing ▁country , ▁without ▁any ▁substitute ▁or ▁trans itional ▁arrang ements ▁being ▁put ▁in ▁place . ▁As ▁regards ▁trade , ▁the ▁parties ▁would ▁likely ▁follow ▁World ▁Trade ▁Organ ization ▁rules ▁on ▁tar iffs . ▁ ▁Re - entry ▁or ▁un il ater al ▁rev ocation ▁Article ▁ 5 0 ▁does ▁not ▁spell ▁out ▁whether ▁Member ▁States ▁can ▁res c ind ▁their ▁notification ▁of ▁their ▁intention ▁to ▁withdraw ▁during ▁the ▁neg ot iation ▁period ▁while ▁their ▁country ▁is ▁still ▁a ▁Member ▁of ▁the ▁European ▁Union . ▁However , ▁the ▁President ▁of ▁the ▁European ▁Council ▁said ▁to ▁the ▁European ▁Parliament ▁on ▁ 2 4 ▁October ▁ 2 0 1 7 ▁that ▁“ de al , ▁no ▁deal ▁or ▁no ▁Bre x it ” ▁is ▁up ▁to ▁Britain . ▁Indeed , ▁the ▁prev ail ing ▁legal ▁opinion ▁among ▁EU ▁law ▁exper ts ▁and ▁the ▁EU ▁institutions ▁themselves ▁is ▁that ▁a ▁member ▁state ▁int ending ▁to ▁leave ▁may ▁change ▁its ▁mind , ▁as ▁an ▁“ int ention ” ▁is ▁not ▁yet ▁a ▁de ed ▁and ▁intent ions ▁can ▁change