Rishi Sunak is set to fight the next election with the Tories having raised taxes by more than any government since records began.
According to the Institute of Fiscal Studies (IFS) taxes will soon amount to around 37% of national income, up from around 33% at the time of the last election in 2019.
That equates to £3,500 more tax per household in just four years.
The next election is expected to be held next spring or autumn, but in theory Sunak could delay it until January 2025.
On current forecasts, the IFS said, there was “no world” in which this parliament – or the period since Sunak entered No.10 nearly a year ago – will be anything other than a tax-raising one.
Today’s analysis is likely to further upset Tory MPs who have been demanding Sunak urgently cut taxes.
In a major intervention last week, Liz Truss urged her successor to slash taxes including reducing corporation tax back down to 19%.
But Jeremy Hunt has warned tax cuts are “virtually impossible” given the level of the UK’s long-term debt.
The chancellor has said his Autumn Statement in November is likely to include even more “difficult decisions”.
Ben Zaranko, a senior research economist at the IFS, said it was “inconceivable” that Sunak would end up having cut taxes overall by the time the country goes to the polls.
“It looks nailed on to be the biggest tax-raising parliament since at least the Second World War,” he said.
He added: “This is not, for the most part, a direct consequence of the pandemic.
“Rather, it reflects decisions to increase government spending, in part driven by demographic change, pressures on the health service, and some unwinding of austerity.
“It is likely that this parliament will mark a decisive and permanent shift to a higher-tax economy.”
Mark Franks, the director of welfare at the Nuffield Foundation, said demographic change combined with slow economic growth was creating “an almost inevitable increase in tax”.
“There will be strong pressure in coming parliaments to raise taxes further to meet growing demand for public services such as healthcare,” he said.