In Scotland, where a separate income tax regime applies, the effective rate climbs to 93 per cent. Under the present framework, unspent pension pots fall entirely outside the inheritance tax net.

When someone dies before reaching 75, their beneficiaries owe no income tax on withdrawals from the deceased’s pension either. IHT is levied at 40 per cent on the portion of an estate that exceeds available allowances.

Pensions face ‘triple tax blow’ as HMRC eyes 93% charge on retirement savings

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Every individual benefits from a £325,000 nil-rate band, supplemented by the residence nil-rate band worth an additional £175,000 provided a home is left to direct descendants.

Couples who are married can pool these allowances, enabling them to hand on up to £1million free of IHT. Yet for estates valued above £2 million, the residence nil-rate band is tapered away at £1 for every £2 over the threshold.

Once fully eliminated, a married couple retains only their joint £650,000 basic allowance.

Sean McCann, a chartered financial planner at NFU Mutual, illustrated the impact using a couple with combined assets of £2million and pension savings totalling £700,000, who leave everything to the surviving spouse and then to their children.

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Before the April 2027 changes, the pensions would attract no IHT, and two residence nil-rate bands worth a combined £350,000 would apply to the family home.

After the rule change, adding the pensions pushes the estate to £2.7million, wiping out the residence nil-rate band entirely.

That erosion alone generates an extra £140,000 in IHT, more than doubling the total bill to £820,000, an effective 60 per cent charge on the pension pot.

The picture worsens dramatically when the surviving spouse dies after 75, triggering income tax on pension withdrawals for the children.

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Pension income stacked on top of their existing earnings could push beneficiaries into the 45 per cent additional rate band.

In that scenario, an extra £219,326 in income tax would fall due, bringing the total tax charge attributable to the pension to £639,326, equivalent to 91.3 per cent of the £700,000 fund.

Scotland’s top income tax rate stands at 48 per cent, meaning beneficiaries there would face additional tax of £653,948 on the same pension pot, an effective rate of 93 per cent consumed by the triple levy.

Mr McCann said: “The changes from April will mean some families will be hit with a triple tax blow, through a combination of inheritance tax on the pension, loss of the tax break on the family home and additional income tax if their loved one dies after age 75.

“’There are steps you can take to mitigate the impact, including ensuring you take your tax-free lump sum before age 75, while it may still be subject to inheritance tax it will avoid an additional income tax charge.”