After last week’s advert claiming Rishi Sunak doesn’t want to lock up paedophiles, the latest attack ad is a bit more reality-based. A bit. It claims fairly that the Tories have raised taxes 24 times and the British people face the highest tax burden in 70 years. So far, so reality based. The claim that is less plausible is that an energy windfall tax will pay for a freeze of council tax. The same windfall tax that has been pledged for so many other spending commitments.

Taxes, as Nigel Lawson often reminded us, pay for spending: if you want lower taxes, you need lower spending. The problem with Labour adopting the rhetoric of the Taxpayers’ Alliance is that, as a shadow minister told the i’s Paul Waugh, totting up all the spending pledges meant “a f****** £700 billion price tag”.“In theory, we are only committed to £280 billion over 10 years but the climate investment pledge can’t pay for everything we’ve said on Northern Powerhouse Rail or full HS2 – we are committed to both.” It is fantasy economics that Rachel Reeves will not be able to bluff and bluster about for much longer.

The advert references closing the non-domicile “loophole”. Foreigners coming to spend and invest in the UK do so on the understanding that their foreign earnings will be outside the jurisdiction of the UK tax regime; their income and remittances to the UK will be taxed just like everybody else’s in Britain. That’s not a “loophole”, that is a sensibly-designed tax principle that encourages foreigners to create jobs and boost the British economy with inward investment. Gordon Brown understood this and left the rule in place for all his time.

Norway’s centre-left government has just discovered what happens when you try to squeeze the super-mobile wealthy. The wealthy are leaving and the government seems shocked. Billions in lost revenue will now have to be made up for by people on lower incomes. There is a lesson here.