The British budget report was unexpectedly leaked in advance, increasing the fiscal cushion to 22 billion pounds.

UK official budget oversight body released an analysis report prematurely showing that the key fiscal cushion has expanded from 99 billion in March to 220 billion ($290 billion) ahead of Chancellor Rachel Reeves' speech. This cushion figure is the largest in UK spending plans since March 2022, significantly higher than the median estimate of 150 billion from survey banks. The key indicator was disclosed as the Office for Budget Responsibility released its budget analysis report unprecedentedly early. In the Labour Autumn Budget, fiscal cushion was increased The expanded fiscal cushion was achieved by increasing taxes by 29.8 billion, including new taxes on gambling and high-end real estate. The document, originally planned to be released after Reeves' speech in the House of Commons, was released prematurely, causing market fluctuations as traders attempted to digest the conflicting information in the report. The Office for Budget Responsibility confirmed the authenticity of the release but stated that the forecast links on their website were "prematurely" live. The agency apologized for the error and stated that an investigation has been initiated. The Office for Budget Responsibility estimates that inflation will be about 0.5 percentage points higher in the next two years compared to the March forecast. As a result of this revision, the yields on two-year UK government bonds have increased by about 2 basis points. Despite the fiscal cushion being higher than expected, economic growth across the entire forecast period has been downgraded to reflect lower productivity. Measures clearly outlined in the leaked document include: introducing additional taxes on residential properties worth 2 million and above, increasing property and savings income tax by 2 percentage points. The document states that pension contributions over 2000 will no longer be exempt from national insurance tax, and the employer's national insurance tax threshold will be frozen for three years from 2028-29. In addition, the government will introduce mileage-based charges for electric vehicles from 2028. The fuel duty freeze policy will be extended until September 2026. The tax-free allowance for corporate income tax will be reduced, raising 15 billion.