One day people will understand that the biggest barrier for trade is the cost of adapting your products to the regulations of different countries... Who sets regulations? Politicians!
So political union is PART of economic union.
So political union is PART of economic union.
Seriously!
"We wanted an economic union, not a political union"
What the **** did you think economic union was?
There are only 2 types of barriers to trade: tariffs & regulations.
Tariff union = Customs union.
Regulatory union = Single Market!
Sorry, but:
"We wanted an economic union, not a political union"
What the **** did you think economic union was?
There are only 2 types of barriers to trade: tariffs & regulations.
Tariff union = Customs union.
Regulatory union = Single Market!
Sorry, but:
And of course, as a couple of the comments are pointing out, the third main barrier is distance, but I've already given my geography lesson for the day. So I'll let you figure out for yourselves which countries are physically closest to us. 
