UK Faces Largest Peacetime Tax Rise Among Developed Economies

What you need to know...

The United Kingdom is projected to see the fastest increase in its tax burden among developed economies, according to the International Monetary Fund's latest Fiscal Monitor.

The IMF predicts that the UK's tax revenue as a share of national income will climb from 37.6% in 2024, when Rachel Reeves assumed the role of Chancellor, to 42.1% by 2031. This rise, the highest in UK peacetime history, equates to an additional £130 billion per year or roughly £4,500 per household.

These forecasts have ignited significant debate concerning the government's economic strategy, particularly as the nation navigates global political uncertainties and domestic pressures on public spending.

IMF forecasts rapid tax burden increase

The IMF, in its Spring Fiscal Monitor, highlights that the projected 4.5 percentage point rise in the UK's tax burden over the current decade is the steepest among the 38 advanced economies surveyed. By 2031, the UK’s tax burden would approach levels seen in France and substantially exceed that of the United States.

This increase is expected to set a new peacetime record for the country, underscoring a marked shift in fiscal policy compared to other leading economies. The report arrives as Chancellor Rachel Reeves attends IMF meetings in Washington D.C., placing additional scrutiny on the government’s fiscal plans.

Economic growth outlook downgraded

Alongside its fiscal projections, the IMF revised its estimate for UK economic growth in 2026. The Fund now anticipates GDP expansion of just 0.8% for the year, a reduction of 0.5 percentage points from the forecast issued in January. This constitutes the largest downgrade among G7 nations.

The IMF attributed part of this weaker performance to the ongoing economic impact of the conflict in Iran, which has led to sharply higher energy costs for households and businesses. These pressures come against a backdrop of existing concerns about the sustainability of the UK’s public finances.

Political debate over fiscal policy

The projected trajectory of the tax burden has prompted sharp criticism from opposition politicians. Shadow Chancellor Sir Mel Stride stated, “Rachel Reeves said she would not tax working people but she is delivering the fastest rise in the tax burden of any major economy.”

He further warned that such increases risk undermining the sustainability of the UK economy. The debate has also focused on government spending priorities, as critics argue that increased revenue is being allocated to social benefits rather than on areas such as defence.

This has fuelled calls for greater fiscal restraint and a review of current budget allocations.

Comparison with other nations

The IMF's report outlines tax burden forecasts across leading economies. France is predicted to see a 1.7 percentage point increase by 2031, with Germany’s rising by 1.2 points, the United States by 0.9, and Italy by 0.6. In contrast, Canada's and Japan’s tax burdens are expected to fall.

The average increase across all advanced economies surveyed stands at 0.9 percentage points. If the UK proceeds as forecast, its tax burden will become much closer to France’s relatively high level, moving further away from that of countries such as the United States and Italy.

Energy policy and North Sea investment

Broader criticism of current economic policy includes renewed debate over the UK’s energy strategy. The government extended a windfall levy on North Sea oil and gas producers, resulting in a headline tax rate of 78% on those profits.

At the same time, new licences for oil and gas exploration have been halted. Business and political leaders, including former NATO Secretary General Lord Robertson and senior representatives of the Confederation of British Industry, have voiced concern that these policies may be discouraging investment and reducing future tax receipts from the sector.

Rain Newton-Smith, Chief Executive of the CBI, said in a BBC interview, “The windfall tax is reducing investment in the North Sea and should be reformed to encourage existing extraction projects.”