Re: Or more accurately..
You can delete #2 or end it after 5 words, it's not relevant, the EU has been sick of the UK for many years without ever suggesting that they leave.
#4 needs to redefine "sensible" and "both parties" as their opposites.
The EU is 27 different countries with a very complicated interlocking set of treaties and obligations. Change any one of those and the others are open to negotiation, which takes about 10 years to make sure that it's actually agreed by everyone and not a passing whim.
Biting the hand that feeds IT
