Ahead of us are six weeks of intense campaigning as Rishi Sunak and Liz Truss vie to become leader of the Conservative Party. Already, each contender has attempted to seize the mantle of Margaret Thatcher, which an outside observer might think odd. After all, the Iron Lady left office more than 30 years ago: Sunak, 10 years old when she was deposed, must barely remember her.

It would be odd enough if the challengers were invoking a long-past leader to win the votes of the party membership. It would be like Tony Blair winning the Labour leadership in 1994 by calling on the memory of Hugh Gaitskell. But there is something yet more odd: each is using “Thatcherism” to mean precisely what they want it to mean.

How else can they both say they are Thatcherites while holding opposing policy positions? Sunak refuses to cut taxes, pointing to the Thatcher of 1980/81 who raised taxes to rebuild the fundamentals of the British economy. Truss promises early tax cuts, seeing herself as the small-state queen of deregulation that emerged in Thatcher’s second term.

I propose two theses. The first is that neither candidate really understands the essence of “Thatcherism”, an inappropriately personalised term for an ideology which had many parents, because it was a set of policies developed as a reaction to particular circumstances rather than a universal creed. The second thesis is that, if the Conservative Party is to develop a coherent, effective and radical set of policies for the 2020s and beyond, it must consign Thatcherism to glorious history.

Margaret Thatcher was a brilliant, unique politician once she won the keys to Downing Street. But she was not always outstanding. As education secretary in Heath’s cabinet from 1970 to 1974, she had been a middleweight at most, raising no objections to the government’s dramatic economic U-turn in 1972.

Britain in 2022 is almost unrecognisable

By the time she was in opposition, rethinking her perspective of the state and the economy, she was by no means alone: she initially supported Sir Keith Joseph to unseat Heath. He was discovering, in his own agonised way, a political platform. It owed a huge debt to Friedrich Hayek and Milton Friedman in academia, and in politics to Peter Thorneycroft and, above all, Enoch Powell. In his old age, Powell was asked if he was pleased that Thatcher had taken up his ideas and put them into practice. He assented reluctantly but added, “I wasn’t sure she understood them.”

Thatcher had the opportunity to implement her adopted ideas because the post-War economic consensus — which prioritised full employment, was open to nationalisation and believed in government control of prices and incomes — all but collapsed. The crisis which unfolded in the 1970s destroyed Heath’s government and would bedevil the Labour administration which followed. In 1976 the UK had to apply to the International Monetary Fund for a huge loan to avoid a sterling crisis, while mighty trades unions came to see themselves as part of a dyarchy with the elected government.

If nature abhors a vacuum, then politics relishes it as an opportunity. The electorate eventually perceived the crisis of the 1970s as a systemic failure and was therefore receptive to radical new ideas. Although the Conservative manifesto of 1979 was more cautious than we like to remember — and Thatcher was very much a minority in her own cabinet in being a true believer until at least 1981 — it was clear that when the time came to choose, then prime minister Jim Callaghan represented the failed past, while Thatcher offered something new.

Yet this is ancient history, the politics of 40 or 50 years ago. The UK was a heavily industrialised economy with sectors which were declining. Trades unions, with mass membership, could assent to or oppose economic policy with devastating effect. The financial sector was heavily regulated and relied on an old guard of gentlemen who had attended the leading public schools.

Britain in 2022 is almost unrecognisable. Virtually all the nationalised industries have been sold off, with the government only retaining significant control in the rail sector. Heavy industry is all but gone, and we prosper through financial services in a light-touch regulation City and through a growing tech sector. Trades union membership (like political party membership) has fallen steeply.

The country is undoubtedly at an inflection point. We have now definitively left the European Union (pace the ongoing wrangling over the Northern Ireland Protocol) and we are negotiating our own independent free trade agreements. Meanwhile, public spending on the NHS and social care is growing year on year, insatiable and almost beyond partisan argument in anything but the outward appearance. Unemployment, at around 1.2 million, is lower than at any time since 1974 (remember under Thatcher it peaked at over three million) but full employment is barely even an aspiration in realistic terms.

There are dramatically more of us, too. In 1979, the population of the UK was just over 56 million. It now stands at 67 million, an increase of about a fifth in only 40 years. We are an ageing society, living longer and suffering from more varied diseases. Meanwhile, the birth rate is slowing.

The Thatcher name has become a false god and a golden calf

An impartial observer would think it beyond belief that aspirant leaders are looking to the policies of 40 years ago to take on the challenges of the 2020s. It would be like German politicians reaching for the greatest hits of Helmut Kohl, or French ministers studying the record of François Mitterand. It is like being given the crib sheet to the wrong exam. Before the Conservative Party can really think about the future and the philosophical approach it will adopt, it must with due ceremony inter Thatcherism and turn to a blank page.

One of the fundamental ingredients of successful leadership is prioritisation: a prime minister taking office must be able to see the wood from the trees, and have broad objectives to which detailed policies are buttresses. Whoever takes up residence in Downing Street in September will have at the top of their list: inflation, the cost of living, energy bills and security of supply, imports and exports, and domestic economic imbalances (the genesis of “levelling up”).

None of these problems is immediately amenable to ur-Thatcherism. How could they be? Different circumstances obtain. Moreover, the gap between left and right has changed — in some ways widened and in some ways narrowed. Free-market capitalism is more or less accepted as a fact of life by both major parties (now that the Labour Party has turned its back on Corbynism and its Marxist roots). Maintenance of the NHS as a public service free at the point of delivery — a budget which grows inexorably — is now a sine qua non of electoral success.

Populist elements of the Conservative Party, inspired by Johnsonian coups de main and the necessities of the pandemic, see government as a force for good, an active participant in both the design and execution of public policy. Naturally, the Labour Party — broadly now a social democratic enterprise — agrees. In some ways we are almost in the grip of a modern form of Butskellism.

If Toryism is to remain vital and attractive, it cannot join a Blairite ghost army in a brutal but undifferentiated battle for the mythical “centre ground”. That leads inevitably to two undesirable outcomes: firstly, the politics of the lowest common denominator, whereby only those policies which are supported across the ideological spectrum gain any serious traction. Secondly, it worsens the disenchantment of the public with the political system. It encourages the sense (which is as real as Cockaigne) that all problems are amenable to solution if only men and women of goodwill can talk sensibly and amicably and each have their voice heard.

But something innovative must take shape. Whether Rishi Sunak or Liz Truss wins, the new prime minister will have no more than two-and-a-half years until the next general election. They should adopt a self-denying ordinance which stops clinging to the Thatcher name, for it has become a false god and a golden calf. Instead they should start work on an election manifesto which distils Tory principles for the 2020s and beyond.

Small government as an enabler rather than an overarching doer; free trade as the path to economic success and a moral imperative; a government which is self-critical and ruthlessly honest with the electorate; a health service which (like all public services) focuses on the needs and experience of the end user; a regulatory system which is designed to promote ease of business and the free flow of capital and ideas; a society which encourages local and community support, doing spontaneously what the state currently mandates. Most of all the new philosophy must provide for a Britain which is absolutely clear-eyed, realistic but confident of its place in the world.

The Conservative Party has ducked important questions for too long. Thatcher’s dominance of rightist politics has become a crutch and the party must now learn to walk independently. Let us bury Thatcherism reverently but finally. Carve out what may even, who knows, become Trussism or Sunakism. The name is unimportant, but the content is all. It must be modern, relevant, effective and popular. And it can still be done.