brussels european union ready start negotiate detail post-brexit transition period britain early new year senior eu official say friday talk future trade take long side already fairly clear structure transition period likely last around two years britain leave eu march 2019 involve london accept almost eu rule without say make could easily engage issue early new year official tell reporters eu executive accept britain offer enough divorce term recommend governments discuss future negotiations start principles future relationship eu would need detail britain want transition would draw full set guidelines negotiators probably summit february march though possibly late official say intention would framework agreement future relations ready time britain leave formal negotiations full free trade agreement would however start britain long member eu negotiator michel barnier say believe full trade agreement negotiate three years could ready end transition period eu official note would cliff edge scenario trade relations transition period end stress eu would agree long transition though specify long eu note britain ask transition around two years eu ready start brexit transition talk early 2018