london prime minister theresa may tell business leaders treat two-year transition period brexit assure try ease company concern britain could crash eu without deal source tell reuters may meet business chiefs glaxosmithkline gsk.l vodafone vod.l hsbc hsba.l major company monday hear want talk britain relationship eu brexit businesses become increasingly alarm slow progress negotiations prospect country could leave trade bloc without new trade arrangement place 2019. point view transitional agreement non-negotiable ... business think two-year period assure happen source say ask may say discussions monday spokeswoman may office say restate position government goal smooth orderly exit one set change businesses people almost business leaders express concern access talent brexit several tell may investment cycle mean decisions come end 2017 start 2018 source say last week two source tell reuters japanese carmaker toyota 7203.t intend build next version auris car british car plant assumption government secure transitional brexit deal decision due end year may finance minister philip hammond acknowledge monday meet businesses need good sense britain post-brexit relationship european union may say business need clarity source say chancellor finance minister say clarity important perfection business chiefs previously complain voice drown disagreement division government hear anything give certainty need plan invest businesses may office say stress importance engage business community design propose implementation arrangements promise continue meet wide variety business voice may join hammond business minister greg clark minister exit eu david davis trade minister liam fox council company attend also include balfour beatty balf.l wpp wpp.l morgan stanley ms.n aston martin ab foods abf.l government say meet come may authority undermine last week fend challenge 30 lawmakers push quit follow disastrous snap election june saw rule conservatives lose parliamentary majority uk pm may tell business chiefs two-year brexit transition assure source