Neither Blair nor any other leader wants much more real sovereignty to leave their national parliaments. They each want to keep their grip on the EU through their control over the Council of Ministers. They don't want to create a monster super-state with democratic power that supersedes nation states. That's just a figment of foetid Europhobic imagining. There is no THEM and there is no Big Plan for us to either join or refuse.
Nothing is planned, nothing settled, Europe is, as always, a continuous conversation.
That's why it's so important for us to be there as full members. Of course, there is a need for sharper debate on what the EU might be. Its own great success as a forger of European peace and confounder of communism has left it bereft of a clear mission. Expansion from the Atlantic to the Urals is the next endeavour - eventually Russia, Turkey, Cyprus, Serbia, Albania, everyone. Some are appalled at the lack of cultural or historical unity there would be among such diverse peoples.