But slashing back the state is no easy task. Health spending as a share of GDP alone has risen from 4pc of GDP to above 7pc in the past 40 years, and is predicted to reach 8.4pc by 2025. Meanwhile state pension spending of £105bn this year could reach £133bn by the middle of the decade.

Despite the splurge, Brexit minister Lord Frost made the case for a low tax, lightly regulated economy at the Centre for Policy Studies this week.

Last year, rising cabinet star Liz Truss also asked Thatcher’s favourite thinktank to come up with ways of rolling back the state, and it devised a £30bn menu of nine options including public land sell-offs. But with the PM against austerity, sources mutter little has been done even on this small change – in fiscal terms at least – as ministers “need to be willing to upset people”.

Paul Johnson, director of the Institute for Fiscal Studies, says turning the clock back to Thatcher would only be possible with “a quite different settlement” on public services such as leaving “a fraction of the population to pay for their own health care, or some large chunk of it, for instance”. Rooting out inefficiencies in the existing framework simply isn’t enough.

The economist points out that Thatcher’s revolution focused on wholesale privatisations rather than cuts to public services, which were deeper under the Coalition between 2010 and 2017. “The obvious difference between the Thatcher years and now is that focus on the market, the movement of the state out of areas.”

That contrasts with the Government’s stated ambitions on infrastructure as Johnson flags up major increases in capital spending underlined by the latest £96bn rail plans. “If I was asked to bet, my bet would be that tax and spending will be higher as a fraction of GDP in 10 years’ time than it is today,” says Johnson.

Tees Valley mayor Ben Houchen, another influential Conservative figure who is leading a major regeneration project on Teesside, argues fears over a creeping public sector are based on a “misunderstanding” and the UK would lose out in emerging industries by standing aside, as interventionist rivals tempt mobile global capital.

“It’s about using the state to leverage private sector investment. That doesn’t mean the state needs to be bigger, just smarter,” he says. “You can have a savvy commercially aware Government that unlocks investment and jobs without it being big and bureaucratic, and often it’s not about more spending, but clever and cleaner regulation to incentivise business to the UK.”

But there has been little sign of that strategic thinking so far from a Government beset by the pandemic and far too willing to turn to tax and spend, according to its critics.

Tice says: “It’s a bit like water going over a waterfall. Once you get so far, you can’t stop it. I think we’ve got less than five years beyond which continual tax rises and wasteful spending become endemic.

“If it goes so far, you’ve actually become a boring European social democracy. And then, frankly, as a dynamic high-growth nation, the place is finished. It’s done, it’s gone.”

The party will likely watch the by-election with eager eyes this week, as an indicator of public support towards a high-stakes debate that will shape the British economy for years to come.