Finance Bill

Perhaps I am not making myself clear. I understand the principle that the hon. Gentleman outlines. I am trying to explain that there is no retrospectivity in air passenger duty. I understand the constitutional point—we will consider that shortly and the Financial Secretary will tackle it—but there is no retrospection in air passenger duty. Although I have an A-level in economics, my background is in being a lawyer. I therefore know something about contracts. The tax is not to do with when the contract is made but, in the case of a service, which often entails delay, when the transaction is concluded through the delivery of the service. The example that the hon. Gentleman gave of the tie was a concluded deal and ownership had passed before the tax change had occurred.