We must tell people the truth,” said Rishi Sunak in Monday’s Conservative leadership debate. He was explaining how government borrowing amounted to little more than taxation deferred. His call for honesty, though, got me thinking: what other uncomfortable economic messages might an honest prime minister level with the public about?

They might start with the unsustainability of the UK’s welfare state. Given the ageing population, cautious assumptions suggest our pay-as-you-go NHS, state pension, and social care system will more than double government debt relative to GDP over the next five decades, absent other policy changes. There are no easy solutions to this. The tax burden is already at its postwar peak, economic growth faces huge headwinds, and you can’t inflate away a triple-locked state pension and promises for hip replacements.

Or what about admitting how certain important sectors are subsidy junkies? Our NHS costs much less than US healthcare in part because we free-ride on drug and treatment innovation financed by Americans. If our universities, rather than taxpayers, bore the cost of non-repayments of student loans, a significant number of them would go bust too.

A candid leader would admit that profit taxes aren’t borne by corporations, but rather workers, consumers and investors. A 25 per cent corporation tax rate, as Sunak intends, would therefore lower pay and raise prices, rather than costlessly extracting revenue from profitable firms.

Our political truth-teller would also clear up misconceptions of where the tax system distorts activity and where it doesn’t. Council tax is low relative to business rates, making land for commercial use relatively undersupplied. Contrary to populist sentiment, Amazon enjoys no tax advantage relative to the high street. Its business model simply avoids the need for expensive inner-city properties with high business rates.

A sincere politician would acknowledge that nuclear energy can’t compete on cost with fossil fuels without an extremely high carbon tax. They’d admit too that jobs are a cost of energy production, not a benefit. To the extent that the net zero transition “creates green jobs”, this represents falling energy productivity and more expensive power.

Populist impulses could be quelled if leaders admitted that market-valued productivity differs enormously across the population, and that top pay typically reflects this. Chief executives are remunerated generously because their effects on companies can be large and shift market valuations by billions. The “gender pay gap” can similarly be explained by the effects of time spent caring for children, rather than the patriarchy.

If a leader really wants to rain down truth bombs, they could admit that “levelling up” is virtually impossible. Nor can any government foresee how technology and trade will alter our ideal economic geography. The best means of improving productivity would instead be to remove land-use planning constraints to allow people and businesses to locate where they are most effective, even if that hollows out certain existing towns.

Leaders hard-headed about growth should worry that Britain is currently 15 per cent less productive than the US or France, yet recognise this comparison suggests that better policy could improve things. An upfront, concerted push to raise GDP per capita requires prioritising private investment over government redistribution, as well as efficiency over “feel-good” regulations.

So, yes, let’s aim for more political honesty about economics. Sunak himself, though, still has a long way to go to become a straight shooter.