In British politics, governing is as much performance art as it is accounting. Even ‘Fiscal Phil’, that most studious scrutiniser of the spreadsheet knows this. Perhaps this is why his green headlines ahead of the budget were about a single use plastics tax, a clampdown on dirty diesels and a push on EVs. These followed a green October, with Michael Gove ditching neonicotinoids and consulting on a bottle deposit scheme, and Claire Perry producing a Clean Growth Strategy that sees huge opportunities too irresistible for a business department to ignore. But the big reveal on budget day showed that, as far as the Treasury is concerned, the future is still grey.