It's odd, and I'm not sure national sovereignty is the issue. The UK government has been banging on about the need for regulation, yet when there is talk of regulation, the UK gov is the first to urge caution. Caution is fair enough, but (I think) it was the free market economic policies followed by us here that lead to a bubble and bust. So maybe a bit more regulation and direction (like Germany) would have done us good. The highs wouldn't have been so high, but the lows might not have been so low.
The intervention they finally got around to doing has saved us from being in a far, far worse mess (see Ireland).
But Mandy, Gordy etc. have been going on about the need for international regulation, so I hope they don't then come out and criticise said international regulation.
I don't know too much about French politics, but why would Sarkozy have an "arch-socialist" as a minister?