Chancellor of the Exchequer Rachel Reeves expanded her key fiscal buffer to £22 billion ($29 billion) from £9.9 billion in March, the official budget watchdog said, in an analysis released ahead of her speech in error. The headroom figure was the most achieved in a British spending plan since March 2022 and well in excess of the median estimate of £15 billion from the banks surveyed by Bloomberg. The key metric was released as part of an unprecedented early publication of the Office for Budget Responsibility’s budget analysis. Bloomberg's Anna Edwards reports.