UK Leads G7 Growth in H1 2026 as Q2 Slows, Energy Cap Looms Over Healey Budget

The UK maintained the fastest-growing economy in the G7 through the first half of 2026, even as GDP growth slowed to 0.4% in the second quarter from 0.6% in the first, according to Office for National Statistics figures published August 13, 2026 (The Guardian; ONS).

The monthly estimate for June 2026 came in at 0.3%, beating expectations for zero growth. That outturn held the trajectory established earlier in the year: GDP rose 0.3% in March against forecasts of a 0.2% contraction, following 0.5% growth in February. The ONS also confirmed Q1 growth at 0.6%, unchanged from its initial estimate, with services contributing the largest share at 0.8% growth across all three major sectors.

The deceleration into Q2 was modest. Services output grew 0.5% in the three months to June, down from 0.6% in the three months to May (itself revised down from 0.7%). Production flatlined at zero growth, following an upwardly revised 0.2% in May. Construction figures were not separately flagged in the Q2 release. Nominal GDP grew 0.8% in Q2 and was up 4.1% year-on-year. The ONS revised full-year 2025 growth down to 1.3% from 1.4%, while 2024 held at 1.0%. Q4 2025 growth was revised down to 0.1%.

Consumer spending grew 0.3% in Q2, supported by hotter weather and the England men's football team reaching the World Cup semi-final. Business investment jumped 1.7%, with analysts pointing to a surge in the IT sector tied to the build-out of computing power for artificial intelligence. Deutsche Bank estimated full-year 2026 growth at 1.1%, above the IMF's spring forecast of 0.8%. The spring IMF warning had been stark: Britain faced the heaviest economic blow from the Iran war among advanced nations, largely through energy channels.

The Ofgem energy price cap jumped 13% from July 1, 2026. Experts said the rise could push millions of households into fuel poverty. Andy Burnham announced 'breathing space' measures including cutting VAT to reduce consumer electricity bills by an average of £45 a year from October 2026.

The broader context here is one of structural tension between headline growth and household-level cost pressure. The UK's G7-leading performance in H1 2026 is real, but the composition matters: Q1 strength drew skepticism from economists who flagged possible seasonality issues, and the Q2 deceleration, while gentle, coincides with a sharp energy cap adjustment that will feed through to inflation data in the coming months. The 1.7% business investment figure, particularly the AI-related IT build-out, suggests private sector confidence remains intact, but whether that offsets consumer drag from energy costs is the central question for the second half.

The political timing is tight. New chancellor John Healey, who replaced the ousted Rachel Reeves, is preparing his first budget for October 28, 2026. Healey inherits an economy outperforming IMF expectations but facing a fuel poverty crisis and the lingering energy-security fallout from the Iran war. The Deutsche Bank upgrade to 1.1% annual growth gives the chancellor fiscal room, but the energy price cap rise and Burnham's VAT-cutting intervention signal domestic political pressure that could shape budget priorities.

Looking at what this means for the coming months, the next ONS quarterly national accounts release on September 30, 2026, will provide the full output, expenditure, and income breakdown for Q2. That release will clarify whether the AI-investment narrative and consumer resilience hold up under scrutiny, or whether the energy shock and production stagnation deepen. The Healey budget on October 28 will then be the next inflection point, arriving just as the energy cap adjustment is working through household finances and the ONS's revised Q3 data lands.

The revision cycle itself warrants attention. The ONS's initial monthly estimates have been subject to meaningful downward revisions, as the May three-month figure moving from 0.7% to 0.6% shows. The Q1 0.6% figure held firm through confirmation, but the pattern of downward adjustments to rolling three-month data suggests the headline numbers can soften as fuller data arrives. For policymakers and markets pricing UK growth, the September 30 release will be the more reliable read on whether the G7-leading trajectory is sustaining or softening into the budget cycle.