The Brexit postponement plan being discussed in Brussels - for hours longer than expected - has the potential to tear apart the Government, the Tory party, and Labour too.
The reason being that its explicit proviso that the UK has to decide by April 11 whether to participate in May’s elections to the European Parliament, or else leave the EU on May 7, WITH OR WITHOUT A DEAL, sets up the debate in the UK Parliament which Theresa May was desperate to avoid.
It tells MPs of all parties they have 20 days to decide whether to opt for a long Brexit delay, a delay that could see the UK in the EU till at least the end of the year, or opt for the Prime Minister's deal in short order, or leave in seven weeks without a deal.
With the EU explicitly raising the possibility of a longer delay, there will be MPs in all parties, including ministers and Labour frontbenchers who view that prospect as trumping party loyalty.
Civil war could break out in both the Labour and Tory parties.
And remember, Mrs May has said a long delay would be over her political dead body.
So if the EU finally announces this complicated formula for a short or long Brexit delay, and a negotiated or no-deal Brexit, MPs and ministers would have just under three weeks to decide what kind of Brexit (if any) they want, when they would want it and whether Theresa May should be evicted from 10 Downing Street before all the daffodils have gone.
This is a Brussels recipe for Westminster mayhem.
We’ll see if it survives the night.