Why the EU won’t become a federal government

I was struck by Larry’s Siedentop’s words from today’s Financial Times (subscription required):

…the new member states will be very assertive once the formalities of enlargement are over. We can expect an unapologetic defence of national interests, a suspicion of encroachments from Brussels and an intense dislike of what might be called lurking double standards in the EU…It will be a pluralist vision rather than a unitary one, a preference for something more like a confederation than a federation. For behind the quasi-federalist form projected for Europe that is promoted, at least intermittently, by France, such countries detect a wish to give the EU some of the attributes of a unitary state. Their contribution could decisively shift the balance of the debate away from that particular vision.