Brussels - The EU's chief Brexit negotiator Michel Barnier on Thursday unveiled five position papers on Europe's stance in divorce talks with Britain and argued that London's position on Ireland was deeply misguided. Here are the main issues raised in the new papers and Barnier's statements to reporters.The issue of the border between Northern Ireland and EU member Ireland is one of the most sensitive in Brexit talks and the new EU position paper puts Britain on the hook to find a solution that preserves the historic Good Friday peace agreement."The onus to propose solutions which overcome the challenges" created by Britain's decision to leave the customs union and the internal market "remains on the United Kingdom," the paper said.Often accused of rigid thinking on Brexit, the EU in the paper echoes Britain in calling for "flexible and imaginative solutions" on Ireland, "including with the aim of avoiding a hard border." However, "these solutions must respect the proper functioning of the internal market" and the "integrity and effectiveness" of EU law.Exit issues Most of the position papers are an attempt by Brussels to clear up what will happen to the flow of individual business transactions that start before Brexit but end after the divorce.In a paper on customs, the EU insisted that "the basic approach to be followed should be that the rules applicable in ... an operation when it commences should continue to apply ... until its completion" after Brexit.The same idea is found in a separate paper on public procurement, in which the EU insists that public, cross-border contracts launched before Brexit should remain legally protected after the split.The papers could be seen as a small win for Britain, as they begin to project the EU's expectations of the UK after Brexit.The EU has refused to broach any aspect of the future trade relationship until Brexit talks had achieved sufficient progress on citizen's rights, the Irish border and the UK's financial bill to leave the bloc.Barnier insisted that the EU's new relationship will require a fresh deal, but added that a "transitional period" was also a possibility but had to be requested by Britain. For a future deal, he mentioned the examples of Norway, Iceland and Liechtenstein, "who have chosen to be a party to the single market, to accept its rules, and to contribute financially to European cohesion".At the other end of the spectrum, he referred to the EU's free trade agreement with Canada which although "very ambitious", is far less complete than membership of the single market. "It is not possible for a third state to have all the benefits of the Norwegian model and the weak constraints of the Canadian model," he warned.