berlin britain must choose range exist off-the-peg model relationship european union leave bloc brussels chief negotiator michel barnier tell group newspapers barnier lead eu negotiations britain last year brexit vote tell handelsblatt side interest maintain close relationship range possible relationships limit way without difficulties stay within internal market would norway model british government reject say another option would free trade agreement like ceta-deal canada even canada-style deal would take several years negotiate ask would specific british model country leave march 30 2019 barnier say european leaders decide weekend britain make enough progress exit negotiations begin work devise future relationship lead concern europe world britain could crash bloc disorderly fashion serious economic political consequences disorderly exit would bring enormous problems mainly britain also us say interview handelsblatt four european newspapers would affect everything food supply healthcare add britain would leave single air traffic space lose take-off land right would long member euratom treaty could long import nuclear material eu hospitals power station process design longer-term relationship eu also fraught difficulties add warn eu would need find ways head british attempt undercut european environmental welfare standards arrange future co-operation defense security policy separate treaty say ward british attempt influence decision-making process area correct remove statement bespeak deal could available brexit barnier say off-the-peg deal open britain post-brexit