First, to raise the money it would not be a one-off levy, but rather a 1 per cent tax for five years on the total wealth — property, savings, you name it — on households worth more than £1 million (the tax is estimated to hit one in six adults).

Second, this five year period is estimated to raise £260 billion — close to the £280 billion the Office for Budget Responsibility says can be ‘directly attributable to the package of support’ announced since March to tackle Covid-19. But total borrowing this year is estimated to be £394 billion. This would still leave quite a significant hole in the public finances, making the wealth tax a far less convincing 'saviour policy'.

It’s no real surprise that this proposal isn’t what it says on the packaging. As I say in today’s Daily Telegraph, wealth taxes don’t work and are perhaps one of the worst possible ways of raising revenue.

Britain’s neighbour learned this the hard way: France’s Emmanuel Macron repealed the country’s own version of a wealth tax two years ago after the policy had led to brain-drain and tens of thousands of wealthy residents fleeing the country.

From Sweden to Austria, European countries have done their fair share of flirtation with some form of wealth tax. Over time, the majority repealed them, as they failed to raise the desired revenue and caused more problems than they solved.

The most obvious problem with the tax is how it destroys wealth over time, eroding a country’s tax base that is crucial for producing revenue in the future. Those who are asset-rich but cash-poor are forced to sell what they own, which the government then takes and uses on a spending spree. This week Argentina has announced a one-off levy on those with assets worth more than £1.8 million, also in the name of paying for Covid.

The money will be used, among other things, to pay for PPE and provide relief for struggling industries. The intentions may be good, but in practice this transfer of wealth will also reduce wealth itself, leading to longer-term implications and an inevitably poorer society.

Today’s report from the commission claims a one-off (five year) tax won't distort behaviour, ‘since it is based on wealth at a (past) point in time.’ It would certainly make it hard for people to avoid it, as it is targeting wealth that already exists.

But this speaks to the moral problems with the tax: a wealth-grab like this breaks the social contract between taxpayers and government. People pay their taxes on the understanding that their money, property and assets belong to them, not the government.

To blindside taxpayers with a new principle — that the state can come and collect your wealth anytime it sees fit — would certainly distort future behaviour, as confidence and trust in the system are undermined overnight.

The report itself acknowledges this: that wealth taxes rely ‘on people not being able to respond before the tax is introduced’ — or put another way, it requires the state to undermine personal autonomy over one’s finances.

Wealth taxes are a form of double-taxation that penalise taxpayers and, in the long run, governments, which find themselves with fewer wealthy residents and an eroded tax base. No amount of theorising (or commissions) can turn wealth taxes into a good idea. What the UK needs right now are creative ideas for its Covid bounce back — not ones that put up even more barriers on our road to recovery.