UK Budget 2026: Healey Finds £20bn Headroom as Iran War Bites

Britain will pay £14bn more in debt interest this year, Chancellor John Healey announced as he opened his first Budget, blaming global trade tensions and the war in Iran for squeezing family finances through higher energy costs and higher interest rates.

Delivering what he called a budget "delivered at a time when global uncertainties and pressures are swirling worldwide and hitting people here at home", Healey set out a plan he said would steer the country through "global economic storms" and give people fresh hope for Britain's future.

Healey paid tribute to his predecessor Rachel Reeves, crediting her fiscal discipline. "She took the difficult decisions required," he said, before declaring fiscal discipline his own first priority as chancellor.

On Iran, the chancellor was blunt: the UK did not want this war. He said it has driven up costs for British families through higher energy bills and higher interest rates, and that trade tensions are acting as a drag on global economic growth.

The Guardian's senior political correspondent Peter Walker noted the speech offered "a very immediate précis of the main political points" — Healey talking up "breathing space" on the cost of living and a break from the Keir Starmer era, while citing "global uncertainties" that, as Walker put it, the chancellor "cannot say" might make his adjustments slightly moot.

What do the forecasts show?

The Office for Budget Responsibility, the government's forecaster, delivered the numbers behind the speech.

Healey confirmed he meets both fiscal rules: day-to-day spending is covered by tax receipts, and government debt — defined as public sector net financial liabilities — falls as a percentage of GDP in the third year of the forecast.

The headline figures:

• Headroom: £15bn in 2029-30, rising to £20bn in 2030-31, according to the OBR.
• Borrowing: 4.2% of GDP this year, 3.4% next year, then 2.9%, 2.1% and 1.8% by 2030-31.
• Growth: GDP expands 1.2% this year, 1% next year, then 1.6% in 2028, 1.8% in 2029, 1.7% in 2030 and 1.6% in 2031.
• Debt: 83.2% of GDP this year, 83.8% next year, then falling to 83.1%, 82.3% and 81.7% over the following years.

The growth numbers mark an upgrade on the OBR's March view. Then, the forecaster predicted GDP growth of 1.1% in 2026, rising to 1.6% in 2027 and 2028, before dropping to 1.5% in 2029 and 2030. Healey told MPs that predictions of slowing growth had proved wrong.

Walker described this section as "statistics-rich" and aimed largely at economists and MPs, but said Healey was "at pains to argue that the government is treating the deficit seriously" — a key element in shaping political and market reaction.

The chancellor even found room for the first joke of the speech, aimed — as Walker noted, in something now almost as traditional as a fuel duty freeze — at Liz Truss and her mini-budget.

Why does the £14bn debt interest bill matter?

The interest line is the budget's sharpest constraint. A £14bn annual increase in debt servicing costs consumes headroom the chancellor needs for anything else, and Healey tied it directly to external shocks: war in Iran and global trade friction pushing up the rates Britain pays.

That framing does double duty. It explains tighter arithmetic at home and positions the deficit as the product of forces beyond Westminster's control — the same "global uncertainties" Walker flagged as the speech's built-in excuse if forecasts move against the chancellor.

The OBR's upgraded growth path gives Healey his strongest card. If the 1.8% expansion for 2029 lands, the £20bn of headroom in 2030-31 becomes real spending room. If the Iran war or trade tensions deepen, both numbers move together — and the breathing space Healey promised narrows on paper before anyone gets to spend it.