Only if you're happy, Minister. I agree; in most cases, that's exactly what's happened. The SDLT case that we'll provide to you, which was retrospective, involved a constant to-ing and fro-ing between avoiders or promoters and the UK Government, where, each budget cycle, the UK Government made changes and the schemes would be adapted ever so slightly and then rolled out again. In the next budget, the UK Government would make another change, and this would carry on. Eventually, I think it was 2012 that the Chancellor said, 'These are these changes, if you do it again, it's going to be retrospective back to today's date.' I think that that's a good example and that provides the backstop that you're looking for there.
But I think we need to be clear that there are two announcements, possibly. There's the announcement of the legislation that's being brought in that may come after that, but there's also this sort of announcement that's a kind of warning announcement. Either, I think, should be valid for, or the Ministers would want to be valid for, the backstop date.
But there are other examples. There's been a recent example in the Finance Act 2019, where, for income tax and corporation tax, there were what were deemed to be voluntary returns where taxpayers—. Normally, if you make your own income tax returns, you know that you get the notice from HMRC to file by 31 January the following year. Now, in those cases, some people were sending in voluntary tax returns. Often, those were linked to avoidance activities, because one of the desires is for taxpayers to seek to protect themselves against discovery, so if you voluntarily send in a return—. And there was a court case that found that such returns weren't actually valid and that would have impacts both for those taxpayers who had already sent in their returns and believed themselves to have obtained the protection of having made that kind of disclosure to the tax authority, but also it would have an impact, potentially, on inquiries that HMRC had conducted into those returns. Would those all have suddenly become invalid? This was a court case that had decided that such voluntary returns weren't valid returns, and so the UK Government introduced legislation to give voluntary returns a statutory basis back to the date of the introduction of the self-assessment regimes for income tax and corporation tax. Now that, obviously, didn't have a statement back to 5 April 1996—there wasn't a statement made then—but that's the sort of thing where I think we need to be careful that we don't preclude the Government being able to take action there.