The Devil tells David Cameron, "Look, I can make you richer, more famous, and more successful than any Prime Minster ever!
In fact, I can make you the most popular premier that ever lived."
"Well," says David, "what do I have to do in return?"
The Devil smiles, "Well, of course you have to give me your soul," he says, "but you also have to give me the souls of your children, the souls of your children's children and, as a matter of fact, you have to give me the souls of all your descendants throughout eternity."
"Wait a minute," David says cautiously, "What's the catch?"