What did David Cameron do by saying Jimmy Carr's tax arrangements were immoral? I suggest there were two things that changed, maybe for good.
First, he made clear what I have known and argued for a very long time, which is that tax is not a simple mechanical process where the application of rote rules, such as the pinstripe mafias "less is best" work. Tax is a complex ethical issue where sophisticated decision making is required to balance objectives - including the obligation to settle the dues to the society of which you are a part. I don't think anyone can now seriously deny that in future.
Second, Cameron exposed the massive hypocrisy that exists on this issue. First, his own on his refusal to condemn others having condemned Carr. Second, his governments in offering massive new offshore tax advantages to large companies right now whilst at the same time criticising Carr. Third, the Tories simply not telling the truth about the general anti-avoidance rule they propose, which even it's author says is n such thing.
But most of all by the tax profession and the absurd right wing think tanks with their crass argument that "it's legal so it's 0K". This is nonsense. Apartheid was legal in South Africa for a long time and it was not OK. Legality cannot be confused with morality. And most of all an ability to get round the law - which is what tax avoidance is - can't even be described as legal.
I think these people - and those not far behind them in the big firms of accountants and lawyers, in the CBI, the IoD and others - all realise the game is changing. That's why big business is organising a fight back - but the ground is now being pulled from under them.
I am well aware that the Times is expsoing all these issues to argue for flat tax - of that I'm sure. But candidly, that will also be rumbled for the morally bankrupt system it really is too.
The winners from all this are the tax justice campaign.
And I admit to be quite enjoying that. Cameron, unwittingly, has helped us no end. It would be churlish not to say thank you.