dublin ireland rule seek special post-brexit arrangements northern ireland fallback option negotiations britain departure eu prime minister leo varadkar say wednesday ireland propose britain eu reach bespeak customs union partnership eliminate risk hard border return northern ireland uk land frontier eu departure varadkar say remain eu-member ireland position negotiations lead brussels course fallback position things work determine secure customs union partnership free trade agreement area britain ireland come post-brexit scenario varadkar tell parliament certainly rule seek special arrangements ireland northern ireland negotiate position preference mean irish border one three formidable issue brussels want broadly solve first stage negotiations britain talk future trade relationship start particularly sensitive give decades violence northern ireland british province whether part unite kingdom ireland around 3,600 people kill 1998 peace agreement fifty-six percent northern irish voters vote remain brexit referendum last year split roughly pro-eu irish nationalists eurosceptic pro-british unionists side fear re-hardening border likely hammer effect economy could reignite violence britain say immigration check border post along 500-km 300-mile frontier post-brexit brussels dublin say london fail explain would square objective state intention leave eu customs union close trade link britain ireland economy also widely consider expose eu future trade barriers varadkar say dublin want sacrifice give free trade britain stage analysis ireland finance ministry show last month 11 15 eu goods expose britain irish export highlight extreme vulnerability brexit irish firm however special arrangement keep northern ireland customs union would raise prospect check require goods move britain proposal firmly oppose pro-brexit unionists province leader democratic unionist party dup prop conservative government british parliament reiterate tuesday could barriers northern ireland rest uk ireland moot possible special post-brexit arrangements northern ireland