The EU will prepare a draft of the U.K. withdrawal treaty that envisions Northern Ireland remaining in the customs union — essentially issuing an ultimatum that London come up with other options or accept that there is no other practical way to avoid the recreation of a border between Ireland and Northern Ireland, the EU’s chief negotiator, Michel Barnier, said Friday.
https://www.politico.eu/article/eu-issues-brexit-ultimatum-on-ireland/