london legislation underpin government plan leave european union pass late stage journey parliament wednesday still face weeks scrutiny become law eight days debate legislation complete committee stage lawmakers debate bill line line try make change government propose word formally know european union withdrawal bill legislation face stag approval low house parliament must make way multi-stage process upper house chamber must agree word become law bill legislation serve two main function 1. repeal 1972 european communities act make britain member european communities forerunner european union effectively end britain eu membership 2. transfer exist body eu law british law design provide legal certainty complex process leave controversial bill face criticism opposition lawmakers campaign group members may conservative party brexit still divisive britain referendum june last year many people include lawmakers want retain much country current eu membership possible others would like reverse vote altogether significant objections far focus several different part bill 1. power government amend eu laws bring onto british statute book 2. extent parliament give say final exit deal 3. government intention fix march 29 2019 law exit day may run minority government slim 13-seat work majority 650-seat parliament thank deal small northern irish party seven conservative lawmakers could require rebel defeat government happen far threat rebellion force government make several concessions plan include wednesday compromise allow date brexit change exceptional circumstances minister also agree great scrutiny parliament process transpose eu law may suffer one embarrass defeat 11 conservatives side opposition successfully demand strong guarantee parliament meaningful vote country final exit agreement minister fight bargain way disagreements issue like power government change eu laws transpose british law government intention transfer across eu charter fundamental right bill clear first parliamentary hurdle september two days debate lawmakers vote 326 290 favor principles bill happen next debate continue low house parliament next year date yet set so-called report stage new opportunity add amendments immediately report stage bill give third read usually last hour general discussion bill follow vote amendments make approve bill pass upper chamber parliament conservatives majority entire process take months complete target end date house lord bill pass unelected upper chamber parliament house lord lord put forward amendments discuss decide turn lord agree amendments bill pass back house commons approval ping pong bill pass back commons debate vote lord amendments new amendments introduce theory bill continue pass back forth lord commons final bill agree upon royal assent bill agree house parliament give royal assent queen formally agree make bill act parliament factbox may 's brexit plan pass parliamentary test come