brighton england britain could stay customs union european union leave bloc labour win power main opposition party say monday put pressure prime minister theresa may divide government brexit labour brexit spokesman keir starmer say party ready grown-ups room take charge negotiations leave eu caution take anything table look britain future tie eu months stick position little different conservative party pursuit clean break eu labour change tack last month suggest power would press remain eu single market transition period smooth britain departure march 2019. starmer word take position government ... would negotiate final deal ... retain benefit customs union single market starmer tell hundreds labour members southern english seaside town brighton subject course negotiations remain form customs union eu possible end destination labour late tell event rather take off-the-shelf arrangement future trade eu final deal want pursue hard challenge try win change relationship single market keep free trade membership possibly sign new treaty challenge may vision brexit move also could deepen divisions labour put want close economic tie customs union odds others say referendum vote mean complete withdrawal steve baker conservative minister work brexit criticize labour plan brexit interest control border desire make opportunities bring britain vote leave european union last year divisions brexit look like split party country reveal deep differences south industrial north england young old urban voters rural areas scotland northern ireland vote remain england wales vote leave labour conservatives struggle keep party together brexit strategy aim call soft departure leftist party hop offer catch-all option voters across divide labour say offer flexibility may government counter stay customs union impose tariff trade external countries allow tariff-free movement goods would betray brexit vote stop britain agree trade deal countries rash ideological red line prevent sensible deal fantastical blue sky proposals pragmatic approach labour grown-ups room stand ready take charge negotiations starmer say labour rid high since win seat expect june election may attempt win strong hand brexit negotiations fail lose conservatives majority party capitalize divisions may cabinet say britain run time largely election negotiate bespeak deal transition way tories conservatives handle brexit tell lot competence say incompetence starmer say labour move attract remain voters last year referendum party keen lose supporters mostly northern england back brexit reticent see future relationship bloc conference pack young voters flock leader jeremy corbyn someone bring change labour members vote debate issue brexit mean public discussion eu policy official agenda centrist members part labour first group call unprincipled anti-democratic stitch-up aim stop differences opinion expose others say would press fight force labour commit stay eu single market customs union even vital go forward put clear red water labour party government brexit pro-eu labour lawmaker chuka umunna say many others mean commit full permanent membership single market customs union continue make argument britain 's labour shift brexit propose stay customs union