David Cameron promised a referendum on the Lisbon Treaty. Quite right, too. The British people ought to have a say on such constitutional matters.
But the treaty is clearly about to be ratified - long before he enters No 10. So ratification will come on Gordon Brown's watch, and Mr Cameron is entirely irrelevant to the process.
That means a referendum would be pointless, because if the vote was 'yes' nothing would change, and if the vote was 'no'...nothing would change. We will be bound by the treaty.