Thatcherism is dead. Long live the European social market. So, in effect, pronounced Boris Johnson, the UK’s Brexiter-in-chief, as he celebrated the ruling Conservative party’s gains in local and regional elections. The prime minister is nothing if not inconsistent.

In January, the UK cut its final ties with the EU. Brexit, Johnson declared, was a moment of liberation. Some imagined that it would mark the re-emergence of let-the-market-rip economics to set the UK apart from the soggy capitalism of its erstwhile partners. Corporatist Germany and dirigiste France worried about the arrival of a low-tax, low-wage, lightly regulated competitor. They misread Johnson.

“Taking back control”, it turns out, means embracing European-style economic interventionism. The march of English nationalism into formerly Labour strongholds in the north has redrawn the political map. The government’s chosen dividing lines now focus on culture and identity. Put aside the crude populism, and its new economic strategy bears the statist hallmark of, well, continental Christian Democrats.

Margaret Thatcher raised the standard for the small state, public thrift, tax cuts, and the “creative” destruction wrought by free markets. Britain’s steel, shipbuilding and coal industries fell victim to her conviction that if a business needed state subsidy it should not be in business. Prosperity was rooted in the endeavours of enterprising individuals.

One supposes she was turning in her grave this week as Johnson trumpeted his organising mission as increased state support for “jobs, business and economic growth”. The scale of the reversal was laid out in his legislative agenda for a new session of parliament. He has called it one-nation conservatism. True Thatcherites might prefer “treachery”.

The agenda puts the state front and centre in the cause of stimulating growth, directing investment flows and “levelling up” economic opportunity in England’s poorer regions. Public money is to be poured into funding increases for research and investment. UK Inc, Johnson says, will “lead the world in life sciences”. Some £400m has been invested in what ministers call the “first UK sovereign space capability”.

If we are to believe the advance publicity, billions are also to be allocated to upgrade the nation’s infrastructure; billions more into life-long learning for those who do not make it to university. This in addition to generous funding for health and education and large bribes calculated to persuade Scotland to remain in the UK union. The Treasury is in despair. Word among the mandarins is that Johnson cannot see a problem without reaching for the government’s cheque book.

The urge to intervene is not confined to funding largesse. Johnson wants a new competition regime to protect businesses and intellectual property from foreign predators. “Strategic” industries and companies at the cutting edge of technology are assured of safeguards. Thatcher saw the state as a barrier to prosperity; Johnson hails it as the incubator of growth.

A kind interpretation of this volte-face would say Covid-19 has brought all but the most fanatical free marketeers to their senses. It has exposed the destructive impact on the public realm of the decade of austerity after the global financial crash. To the extent that the economy emerges in reasonable shape from the pandemic it will be because the Treasury abandoned its fiscal fundamentalism.

Johnson, though, is driven by politics rather than conviction. If there is such a thing as “Johnsonism” it is whatever best serves his personal ambition. Brexit required a new coalition of traditional shire Tories in the south and erstwhile Labour voters in some of the least prosperous parts of the north. These “red wall” seats once bore the brunt of Thatcherite economics. They are now an essential pillar of the prime minister’s support. And they want public money — lots of it.

How long this coalition can last is another question. Affluent conservatism has not given up its preference for small government and lower taxes. Tory voters in the south will not be inclined to open their wallets to pay for regeneration of the north. The extraordinary rise in public borrowing during Covid-19 at some point will demand a reckoning.

Look at the arithmetic and, surprise, surprise, it does not add up. Even as he promises more spending, less borrowing and a freeze on tax rates, the Treasury predicts a severe financial squeeze. Johnson will not be able to keep his promises. But then he has never been much troubled by such details.