“We can’t leave welfare untouched,” Rachel Reeves told Channel 4 this week, as she hunts for autumn statement savings. Those were bold words from a chancellor who ditched major welfare reforms earlier this year. Stubbornly high borrowing means she is now reportedly looking to scrimp £1.2 billion from tightening tax breaks on Motability, the scheme that helps disabled people lease cars using their benefits.

I’m all for cutting unnecessary outlays on working-age welfare. But how long will these self-imposed political constraints on spending last? Governments will squeeze pennies from the working-age poor, it seems, before even daring to question the vast entitlement programme that grows bigger and more unjustifiable every year. I’m talking about the triple lock on the state pension, of course: Britain’s most egregious welfare measure.

Yes, welfare. Label the state pension that way and the retired recoil. “We paid our stamp,” goes the cry. Yet the state pension is a pay-as-you-go transfer from working-age taxpayers to retirees. It’s not funded by some magical “pot” of national insurance contributions. It’s redistributive welfare to the elderly, as seen by the triple lock’s original justification.

The triple lock was introduced in 2010 to address the state pension having drifted far behind working-age earnings after decades of price-only uprating. The policy was seen as a medium-term fix for improved generosity. The state pension would rise each year by the highest of inflation, earnings, or 2.5 percent, ensuring an ever-improving relative financial position of recipients.

This was social protection for pensioners against poverty. But it provided unexpected windfalls to all coming retirees. Nobody saving through the 1980s or 1990s would have expected it. And it had one glaring flaw: no end point. No target level. No statement of what transfer was acceptable, beyond which the policy could be scrapped. Instead, the triple-lock introduced a ratchet that made the state pension more generous over time, its structure guaranteed to make it increasingly expensive relative to the size of the economy.

And so here we are. The chancellor now mulls cuts to disability benefits and has hiked the tax burden to its highest level since the 1940s. Yet state pension spending climbs relentlessly. By 2029–30, the Office for Budget Responsibility (OBR) estimates the triple lock will cost £15.5 billion more than if the pension had been re-linked to earnings since 2010. Compared with price indexation, it’s £22.9 billion. That’s equivalent to 2 or 3 pence on the basic income tax rate, every single year.

That degree of redistribution was never intended. The government originally predicted the triple lock would raise the state pension by 0.2 percent a year faster than earnings, on average. The 2.5 percent uplift floor was designed as political insurance to avoid PR disasters like Gordon Brown’s infamous 75p state pension rise. But weak wage growth and low inflation meant that this 2.5 percent backstop kicked in more often than expected through the 2010s. The result is a triple lock that will be three times more expensive by the end of this parliament than originally envisaged.

The case for abolishing this mechanism now is overwhelming. First, the triple lock will meaningfully worsen our long-term debt problem unless scrapped. State pension spending is already about 5 percent of GDP. The OBR forecasts it will reach 7.7 percent by the early 2070s. Over half that increase — 1.6 percentage points of GDP — comes not from population ageing but from the triple lock. In today’s money, that’s £50 billion a year, necessitating significantly higher taxes still on a relatively smaller working-age population.

Second, the triple lock still has no coherent target undergirding it. Question it and someone replies: “Could you live on £230.25 per week?” No, but in my vision, a state pension would merely protect against absolute penury, with private retirement saving encouraged and the norm. But even if you think the state pension should be higher than I do, it’s not clear why the policy should guarantee ever-rising relative comfort for pensioners. Set the level you want, and if the goal is to protect a living standard, link that state pension to inflation. If the goal is to maintain parity with workers, then link it to earnings. But pick one principle and stick to it.

Third, the triple lock injects huge uncertainty into both pension planning and the public finances. Tied to three possible uplifts each year, it’s impossible to predict accurately how generous it will be or how much it will cost over decades. The Institute for Fiscal Studies says the state pension’s value in 2050 could range anywhere from 31 per cent to 37 per cent of median earnings, depending on macroeconomic outcomes. This is no certainty for retirement planning, let alone public budgeting.

Finally, the triple lock is ill-targeted at those in genuine need. Many pensioners who benefit from the ratchet are doing well, and material deprivation remains at far lower rates for them than among working age families. Continuing this policy hands blanket income boosts to all pensioners, not just those in need, all paid for in part by efforts to pare back working-age welfare.

I’m sorry, but I don’t care about the politics. We can’t continue to pretend this is either sensible or just. The solution is not complicated. Legislate now to end the triple lock in, say, 2029. Pick one uprating index — earnings or prices — and stick with it. Integrate it into official forecasts and dare other parties to commit huge sums to reversing it. The specific details matter less than ending the ratchet as soon as possible.

I first made this case publicly on Newsnight in 2014, when it was still economic and political heresy. Today, it’s economic orthodoxy. The IFS describes the triple lock as unpredictable and costly, raising major fairness concerns. No expert thinks it is sustainable. The only question is whether politicians will take the heat and dismantle it willingly, or wait until a fiscal crisis compels them to.