I am getting very strong signals that in the UK we have been focussing on the wrong European Research Group amendment in respect of damage to Theresa May's Brexit plans.
It is the one that rules out even a temporary separate customs arrangement for Northern Ireland that is causing acute anxiety among Brexit negotiators.
Because they think it destroys the backstop clause for Northern Ireland, regarded as the guarantee there'll be no hard border with the Republic.
That in turn would put in jeopardy the entire Withdrawal Agreement - which if it collapsed would lead to a no-deal Brexit.
In Brussels they are concerned that May has been out-maneuvered by Jacob Rees-Mogg and the Brexiters of the ERG, many of whom would prefer a hard Brexit to any other outcome.
Obviously May believes alternative UK-wide backstop proposal can be sold to the rest of the EU. But my sources say that is just wrong.
They would say that. But this is messy.