Who’s for it, and who’s against it.
Spain, Poland, Austria, and Belgium are backing the concept, France, UK, Germany and the Netherlands are against.
It seems that the more up-and-coming, politically and economically unstable ones are looking to the the EU for more centralized (and with luck, fair) power partitioning. Poland is still waiting on the doorsteps of the inner circle Europe, so you take good will where you can get it? Austria’s still awaiting the verdict on its eastern European investments, Spain struggling with higher unemployment and general economic ruin, Belgium barely able to keep the country together.
Bigger states like France and Germany want to retain more sovereignty, and it would look both politically untenable and silly to hand over more power when both believe they control the institution anyway. In the UK and Netherlands, the shift to the right has a distinct and not at all unsurprising anti-EU slant to it.