"that would be acceptable to the EU,"
There's a lot of basic 'point-missing' here
What is acceptable to tHe E.U. really features very small here - the point is far more basic than that
Ireland was partitioned in the 1920s and the residents made citizens of two different nations - just have to put yourself into the position of having to identify yourself if you wish to travel from Luton to Hitchin - simple as that
That led to many decades of bitter resentment and eventually open warfare
The end of the fighting brought about an attempt to bring the two groups together - a major step in that process was the removing of all visible signs of the border.
Now Britain stands to turning the clock back thirty years
They have to be joking!
Jim Carroll