I imagine a few commentators will see that last line as a veiled attack on the Tory leadership, given that they're committed to the tax rate too. But, as Tim Montgomerie says over at ConservativeHome, and going off conversations with Tory types, I doubt that Cameron and Osborne would disagree with the thrust of Boris's article. There are even some murmurings from inside CCHQ that the 50p rate might damage the cause of compassionate conservatism – as it could entail higher taxes for the less well-off, to make up for any reduction in the tax take.
Sure, it's dispiriting that Cameron & Co. aren't making this case now – particularly as the City is looking towards them for a routemap through the post-recession landscape. But there’s a fair likelihood that they'll start sounding more like Boris after the election.