Finance Bill

The hon. Lady is right and I thank her for that additional argument, which reinforces my case, as it was intended to do. The important point is the conditions that apply when the transaction is made. Transactions are irrevocable—one buys or one sells and, at that point, one must make a definitive calculation of the costs and gains. I repeat myself because I believe that the hon. Member for Bishop Auckland has some difficulty in grasping the notion of retrospectivity. If conditions are subsequently changed by a Government tax decision, which applies to the transaction, even though at the time no one could know that the change would occur, retrospectivity has clearly taken place. If we vote for the amendment—and one never knows in a democratic Parliament how many colleagues will go through the same Lobby—we must act responsibly and accept that the consequence of voting for something is that it may pass into law. I recognise that, if that happens, the Government will lose revenue. I have not made the calculation but I take on board the figure of £100 million or £120 million, which is not insubstantial. I am always careful about voting for a measure that will cost the taxpayer £100 million to £120 million. Perhaps the phrase ““cost the taxpayer”” is a little unfair because the taxpayer had no more idea than anybody else that the Government were proposing the measure. In every society that operates under the rule of law and in a market economy that is run on sound principles, the principle that there should be no retrospectivity is so important that establishing it is worth £100 million or £120 million. If the Government are defeated, that will convey a signal to them and subsequent Governments, who may be tempted by retrospectivity, that it is expensive because the House of Commons may rightly take a principled stand. Our predecessors for generations and centuries have upheld the principle that the House should not legislate retrospectively, whether for tax law or other laws. I leave aside the special circumstances of tax avoidance schemes. We in our generation should uphold the principle that I have outlined. If the cost of doing that in the current circumstances is £100 million or thereabouts, I fear that it must be borne in the higher and longer-term national interest.