A senior Labour MP has called for an investigation into a leaked Budget forecast that reportedly moved financial markets. Dame Meg Hillier, a senior Labour member, expressed concern after a news report published a key tax change before the Chancellor addressed Parliament. The leak, which detailed a potential tax adjustment, reportedly caused market volatility. The Treasury has been urged to examine the incident. The report was published by a media outlet, though the specific source was not named. The Chancellor is scheduled to present the full Budget in the coming weeks. The leak raises questions about the timing and security of sensitive fiscal information. The Labour Party has not yet commented on the broader implications of the leak. The incident highlights ongoing concerns about the handling of economic announcements. The Treasury has not confirmed whether it will take action. The leak may affect public confidence in the government’s fiscal planning. The details of the tax change remain unclear. The situation has prompted calls for greater transparency. The government is under pressure to address the issue.