UK Treasury Probes Leak of Bank Tax Budget Details

The British government has launched an investigation into the leak of market-sensitive information from the October 28 budget. The probe, led by the Cabinet Office's Government Security Group, follows a Bloomberg report that accurately detailed a temporary bank corporation tax surcharge hours before Chancellor John Healey delivered his formal fiscal statement. The early disclosure caused bank shares to rally, prompting the Treasury Committee to urge the Financial Conduct Authority to investigate the potential for market manipulation.

HM Treasury Permanent Secretary James Bowler confirmed that no banks or trade bodies were briefed in advance. However, he acknowledged a "necessary widening" of the circle of knowledge within the government to prepare for the budget's delivery. This incident follows a previous security breach in 2025 involving the Office for Budget Responsibility.

Treasury Committee Chair Dame Meg Hillier has expressed skepticism regarding the inquiry, describing a pattern of "dead-end investigations" within the Treasury that rarely identify culprits. Hillier argued that the Treasury still has questions to answer regarding how specific details reached newsrooms before Parliament was informed. Chancellor Healey is expected to face questioning from the committee on Wednesday afternoon.