london prime minister theresa may say wednesday would permit delay britain departure european union exceptional circumstances bow criticism party government plan fix exit date law decision compromise conservative lawmakers last week rebel parliament inflict embarrass defeat may debate legislation end britain eu membership legislation formally title european union withdrawal bill late approval move next stage parliamentary process although still face weeks scrutiny become law may head second rebellion agree government plan define date britain eu exit march 29 2019 temper insert proviso allow date change necessary power use would extremely exceptional circumstances short possible time may tell lawmakers parliament approve new date junior brexit minister steve baker add could envisage date bring forward passage bill next stage overshadow resignation may senior ally government damian green may request internal investigation find breach government code conduct destabilise resignation add political difficulties may face try deliver brexit backdrop divide parliament electorate question ability meet already tight timetable want negotiate transition deal brussels march reassure businesses seal long-term trade deal october brussels say detail trade deal likely take much long britain transition period must end 2020. addition may government undertake huge legislative task transfer exist body eu law british law leave order provide legal certainty businesses may allow brexit delay exceptional circumstances