BRITS are to be clobbered by the highest taxes since just after World War Two to bankroll the massive spending splurge.
And the cost of living could hit a 30-year high, the Treasury watchdog warned.
The Office for Budget Responsibility said inflation could reach five per cent next year — the highest since 1992.
In the bleakest scenario, it could soar to 5.4 per cent and send interest rates up.
But Rishi Sunak dangled the prospect of tax cuts before the next election as he declared: “By the end of this Parliament, I want taxes to be going down not up.”
Treasury insiders said the Chancellor wants to cut levies on working people before the election expected in 2024.
High inflation, rising taxes, poor growth keeping living standards virtually stagnant for another half a decade.
But taxes are set to rocket to over 36 per cent of GDP (the nation’s income) by 2026/7, according to the watchdog.
This includes council tax and National Insurance hikes in the coming years.
With his March and October Budgets, Mr Sunak has imposed the biggest single-year tax hike since Black Wednesday in 1993. Overall, by the end of this Parliament Britain will have the highest tax burden since 1951.
Spending is set to peak at over 50 per cent of GDP — the highest since the war, before settling at levels not seen since the 1970s.
The sums caused jitters on the Tory benches, with ex-PM Theresa May leading calls for the party to return to its low-tax roots.
Institute for Fiscal Studies director Paul Johnson said: “This is actually awful. Yet more years of real incomes barely growing. High inflation, rising taxes, poor growth keeping living standards virtually stagnant for another half a decade.”