More evidence that it is true has appeared recently - Emmanuel Macron has let the cat out of the bag. He says that the EU will not let the UK leave the "backstop" customs union unless it agrees to allowing EU fisherman full access to British waters.
https://www.theguardian.com/politics...al-in-brussels
But surely the "backstop" is only there to prevent there being a hard border in Ireland?
The Irish backstop has been created by the EU as a device to cling on to Britain and prevent it from signing its own trade deals. The hard border issue is just a pretext.