london britain fail agree free trade deal eu plan leave bloc 2019 seek transition period avoid worst-case scenario crash without agreement lawmakers parliament upper house say house lord eu committee report brexit deal deal say thursday britain consider extend membership european union set late date leave give government long negotiate trade deal overwhelm weight evidence suggest deal would bad possible outcome uk term economy security environment citizens right say michael jay member lord eu committee former head britain diplomatic service britain prime minister theresa may hop progress brexit talk collapse last minute monday northern irish ally denounce propose offer border ireland may find difficult come formula satisfy eu member ireland want avoid creation hard border northern ireland dup party say british province must quit eu term rest uk clock tick march 2019 exit date report say big risk factor may trade deal shortage time despite scepticism brussels tight timetable may chief negotiator david davis clear want full post-brexit free trade deal seal time britain leave support david davis ambition secure comprehensive agreement 29 march 2019 almost nobody outside government think possible jay say brexit deal worst-case scenario britain lord committee