He is not offering an In or Out referendum. He is definitely for staying in.
What he does say is that if anymore powers are to go to Brussels, we will have a referendum on that. Most of the rest of Europe did that before the Lisbon Treaty was ratified but Brown denied us a say.
The Conservatives have a very poor record of giving away to Europe. We were not permitted a say under Heath when we joined in the first place. We were not asked if we wanted to join the Exchange Rate Mechanism, and that cost us £billions.