Is there a more divisive money topic than the state pension triple lock? To some it’s a well-earned lifeline in retirement, to others it purely serves to exacerbate the wealth gap between young and old.

It is neither of those things, but the truth is that it is becoming increasingly difficult to defend.

As we approach Rachel Reeves’s consequential autumn budget, there is much talk about how she might tax us more, but rarely is a word spoken about the spending cuts that she needs to make.

The Office for Budget Responsibility, the spending watchdog, has said that the triple lock will be costing us £15.5 billion more a year by 2029 than if the state pension increased in line with earnings alone. This is three times what it was forecast to cost when it was introduced, and now seems utterly wasteful given that pensioners can be protected from rising prices for much, much less.

Yet with nearly 13 million people collecting the state pension, it is feared that politicians dare not touch the triple lock — despite its colossal, and unnecessary, cost.

• The exact year that the triple lock will bankrupt the state pension

When the triple lock was introduced in 2011 it was entirely justified. The state pension had lagged behind the rising cost of living, leaving the pensioners who relied on it poorer and more vulnerable.

Since then, it has increased the value of the state pension in real terms — up and beyond the cost of living. So much so in fact, that many pensioners now have more disposable income than working households.

Yet the triple lock is still in place. At this rate, welfare spending including the state pension will cost more than is raised through national insurance contributions by 2036.

The Institute for Fiscal Studies, a think tank, has found that the state pension age would need to rise to 74 by 2068 to sustain the triple lock.

Dismantling the triple lock does not mean leaving the state pension at the mercy of inflation. The triple lock is the promise to increase it with the highest of either inflation, wage growth or 2.5 per cent. Removing just one of those elements would save us billions of pounds.

What’s more, the triple lock mechanism is fundamentally flawed because it guarantees that the pension will rise more than necessary. When inflation spikes, you typically see wages rise the following year in response. This means that the triple lock grants pensioners two successive pay rises. The state pension will rise 4.8 per cent in April due to wage increases despite inflation this week holding still at 3.8 per cent.

The 2.5 per cent element also means that the pension will inevitably always rise by more than the Bank of England’s target inflation rate of 2 per cent.

Perhaps the biggest myth about the state pension is that it is an earned entitlement. Yet the state pension was introduced as a benefit to protect the poorest from poverty in old age, and it remains a benefit in legislation.

• Save the state pension — by taking it away from the under-75s

National insurance contributions pay for the state pensions of today’s retirees, they are not squirreled away and invested for you to collect when you are ready.

The state pension spending crisis needs to be addressed as our older population swells and piles demand on working taxpayers.

Something needs to give. When all assets are taken into account, roughly one in four pensioners are considered to be millionaires. It’s delusional to suggest that the triple lock can continue in its present form, but dismantling it should come alongside reform.

We need to wean pensioners off the state and incentivise responsibility and investment when it comes to retirement. Australia means-tests the benefit, but at the same time has an effective private pension system that is enabling savers to build substantial funds and enjoy strong returns.

In Britain there’s little appetite to stop the tax-and-spend cycle. The shadow chancellor. Mel Stride, has admitted that the triple lock is unsustainable, but not many ministers have dared to agree even though it is obvious that the triple lock is a luxury we can no longer afford.

We are spending well beyond our means and many pensioners recognise that. It’s patronising to suggest that they wouldn’t vote for a party that had the sense to axe to triple lock.

Indeed, doing so would demonstrate that the chancellor is an economist first and politician second. The triple lock has served its purpose and it is time it was put out to pasture.