The EU fought hard to get two legal precedents :
1) that international treaties preceed the constitutions of member states (and any and all other laws).
2) that the European Commission would be allowed to agree to international treaties on behalf of member states.
There is nobody that can stop this that isn't already in power and Volcker can push this through without ratification by any kind of elected body. Stopping it can only be done in the United States, where it actually has to pass parliament ("congress").
At least now we know why there is no "democratic" in the "European Union" name.