The Government's latest possible Brexit plan B, the idea of replacing the widely hated Northern Ireland backstop with a bilateral treaty between the Republic of Ireland and the UK, is never going to work.
For the EU, it is simply crackers.
The whole reason for the backstop being in the Withdrawal Agreement that sets out the terms of the UK's divorce from the EU is that the Republic's border with Northern Ireland would, after Brexit, be the external border of the EU's single market - and therefore has to be governed by a treaty between the UK and EU, and not one between the UK and the ROI.
An official from an EU capital also questioned whether the Republic could possibly accept "a bilateralisation that would deprive it of the clout of the EU".
For what it's worth, about half the cabinet seem to know this idea is never going to fly. One senior minister scathingly said about the plan "we need to think out of the box given where we are but I am not sure we can dignify this as an idea".
Another added: "If we are going to get Brexit it's us who will have to compromise, and especially the Brexiteers; the EU is simply never going to move that far".
So another way out of the Brexit impasse for Theresa May bites the dust.
And as the minutes to Brexit day on 29 March keep ticking past, the roadblocks just keep being erected.
One important new one is that Leave Means Leave, the cross-party pro-Brexit campaigning group, has appointed silk and solicitors to sue the Government to make sure the UK can participate in elections to the European Parliament in May, in the event that the UK applies for and is granted to a delay to Brexit day.
Leave Means Leave will also write to the Electoral Commission this week to make sure that the Commission has the wherewithal to oversee those elections, if it comes to that.
You might wonder why a Brexit movement would want those elections to take place.
It could be a gambit of semi genius by them - because under the proportional representation system used for those elections the UK would probably send to the European Parliament a preponderance of MEPs who all hate the EU.
This is all the more likely because Nigel Farage has confirmed that he would re-enter active politics as a candidate for a brand new party, with the name - you guessed it - of the "Brexit Party".
He told me that he had given his blessing to another former UKIPer, Catherine Blaiklock, to set up the new party. And that although he he has no desire to become a campaigning politician again, if the Government "drops the Brexit ball, I will be back".
For those who remember when Millwall supporters were the most truculent and troublesome in the world, the outcome of UK elections to the EU Parliament in just four months would probably be the equivalent of sending Millwall supporters into the Vatican for the Easter service.
Which could be seen as performance art on a national scale - or may better be seen as a warning to the rest of the EU not to allow the UK to delay its Brexit, should the Government be forced to request a Brexit delay (as per my note of earlier Sunday).