Liz Truss’ fallen star has been rising again of late (at least a few degrees above the horizon) as gilt yields return to the heights they reached during her brief premiership. Together with sluggish GDP figures this has led many to wonder whether she was not right, after all, to make growth the absolute priority of her economic policy.

Whether she can maintain her momentum following her latest intervention, adding her name to the 50 Conservative MPs calling for the abolition of inheritance tax, is another matter. There would be nothing more fatal to the Tories than to go into the next election offering one tax cut – for millionaires – after having raised taxes for ordinary working people.

Such a policy plays straight into the narrative that the Tory party cares only about the wealthy

There is no sign that Rishi Sunak is minded to adopt this policy, and for good reason. Conservative MPs always get excited about polls which suggest inheritance tax (IHT) is an especially unpopular tax.

But what people like to tell pollsters and what they would think in the event of the Conservatives introducing a policy to eliminate IHT are two very different things. Such a policy would play straight into the narrative that the Tory party cares only about the wealthy, and is prepared to tax the poor in order to reward the rich.

Just look at the optics: millions of people on very ordinary salaries woke up in April to find themselves paying a higher rate of National Insurance (NI) contributions. Year by year, many more people are being dragged into the 40 per cent tax bracket due to fiscal drag. We have all been told by the Chancellor that this is essential, and that we must put up with pain now in order that the public finances can be restored.

How would that go down if we were suddenly told that there was room for one tax cut after all: one which favoured people who stood to inherit over a million pounds? (That is the effective minimum threshold for IHT where an estate involves a family home being inherited from two parents.)

There is one tax crying out to be abolished, but it isn’t IHT, it is NI contributions. This is a tax which falls exclusively on earned incomes, and is weighted towards earnings at the lower end of the scale. The idea that it is some contributory pension scheme, or welfare insurance scheme, is bunk. There is no such fund. NI is an additional income tax which falls on working people, plain and simple. It does not apply to those who are living off their investments.

As it happens, I would abolish IHT, too, but not in a way which would please those MPs crying out for tax-free inheritance. I would stop taxing estates and tax legacies instead – not punitively, but simply applying the same level of income tax as on any other kind of income.

That would be the imaginative policy for the Conservatives: to replace income tax, capital gains tax, IHT and NI contributions with one, universal tax which treats all income and gains equally: a flat tax, in other words.

It doesn’t have to be absolutely flat; to aim for a two rate tax at, say, 20 per cent and 40 per cent, would seem reasonable to me. In practice it would mean lower taxes for workers and slightly higher taxes for people who live off their investments or inherited money. That would be an economically-liberal policy which the Conservatives could sell to the country.

Will it happen? Probably not, because in spite of an outer skin of economic liberalism which has characterised the Conservatives at least since Mrs Thatcher’s day, the party retains a soft, patrician underbelly preoccupied with the defence of wealth and privilege, while tossing crumbs to the poor. We need a proper Liberal party to challenge this tendency, but sadly that is another story.