It is time to resuscitate Margaret Thatcher’s catchphrase: “There is no alternative.” With a twist, of course. Back then, “Tina” was deployed in favour of an economic model that gave us badly distributed low growth, shambolic rip-off privatised utilities, a housing crisis and social insecurity. It is now devastatingly clear that there is no alternative to discarding this failed experiment.

Yet this week, our supposedly Labour chancellor, Rachel Reeves, will take a scalpel to departmental budgets already devastated by 15 years of austerity. Our government has robbed most pensioners of the winter fuel payment, and announced £5bn worth of cuts to disability benefits, which strip support from citizens unable to independently clothe themselves, or who need an aide to use the toilet. By the time of the next election, according to the Joseph Rowntree Foundation, all households will have suffered a fall in living standards, but the poorest will be clobbered twice as hard. This, under the rule of a party founded to represent the interests of ordinary people.

The British public could be forgiven for believing they are imprisoned in a political Groundhog Day. They wake up, their leaders tell them they are awfully sorry, but they are going to have to make yet more unfortunate cuts – but this time, pain will be rewarded by the coming prosperity. A thousand sleeps, another thousand sleeps – and the nation wakes to the same speech. Here’s the bad news: on our current trajectory, you’re going to hear that speech for the rest of your life, whatever your age.

For those who fret that the monotony will bore them rigid, fear not: things will not remain the same. After all, each cut inflicts more pain than the last, hacking away at a public realm and social expenditure already shrunken by the previous round of slashing. There are many reasons why politicians are going to keep pointing to an ever shrinking pot of money. An ageing population imposes ever greater costs, and the number of Britons aged 80 and over is set to more than double in the next 40 years. Soaring defence spending will gobble up expenditure – and with weak returns for the wider economy. Costs imposed by the climate emergency are set to treble in the next quarter of a century. High levels of immigration poured billions of pounds of additional tax revenue into the exchequer: satisfying demands to close our borders accordingly comes with a price tag.

The 2008 financial crash represents the moment that social progress ground to a halt in this country. Sure, scientific and technological advance continued: smartphones got more features, the internet was faster, artificial intelligence is marching on. But by the time the Tories were ejected from power, real wages were still lower than when Lehman Brothers collapsed. The Trades Union Congress estimated that the average British worker would be £10,400 a year better off if real wages had grown at their pre-crash trend.

The Institute for Fiscal Studies estimated that the last government left the purchasing power of school budgets 4% lower than when they took power, our National Health Service is defined by permanent crisis, while technical experts raise alarm bells about the safety of creaking infrastructure. Life expectancy remains lower than before the pandemic – and growth in our lifespans was shuddering to a halt before Covid, and already falling among poorer English women. From pothole-riddled roads to ever more soulless and empty high streets, a sense of decline has become a fact of life.

There is no alternative but to abandon this decline, precisely because it is so intolerable. An expectation that life will improve – not least for each successive generation – is hardwired into western society. The death of that optimism has had increasingly cataclysmic results. It has bequeathed rightwing authoritarianism, which increasingly leaves the survival of democracy an open question. The US spirals into naked authoritarianism: that would once have seemed a fantastical prospect, but who would rule that out now for European nations, including our own?

An economic model that prioritises assets over investment has failed. Our social fabric cannot absorb this relentless assault on the public realm. To confront our current emergency, some Labour MPs have floated a wealth tax. They risk the wrath of a leadership that is as intolerant of dissent as it is devoid of vision. This is hardly a gimmick or an empty slogan. Back in 2020, a team of accountants, economists and lawyers set up a Wealth Tax Commission. They weren’t messing about: one of its main architects specialised in helping private clients navigate the British tax system, and therefore knew its loopholes inside out.

Their proposal: a one-off wealth tax on millionaire couples for five years would raise £260bn. They sought to learn from wealth taxes in other countries, not least about what didn’t work. They sought to deal with potential pitfalls – like those who are asset-rich but lacking enough cash to satisfy the tax collectors. One in 14 households targeted by their proposed tax fell into that bracket, they concluded, but they could pay what they owed over five years, and even longer when applied to private pensions.

Here is just one suggestion, and it needs updating, but it is a detailed, serious piece of work by experts who know what they’re talking about. Those who deem such proposals unfeasible should consider our current plight. An economic model based on permanently stripping away security from most of the population is simply not sustainable. Human misery aside, it has already spawned profound disillusionment and despair, which rightwing populism feeds off. If taking the scalpel to public expenditure bred prosperity, Britain would now be booming. Instead, it has condemned us to stagnation and decline. Rail against abandoning our failed economic model all you like, but if voters conclude there will be social decay whoever they vote for, faith in democracy will die. We have to drastically change course – there is no alternative.

• Owen Jones is a Guardian columnist