A full investigation is underway into pre-Budget leaks from within the Treasury which impacted markets and business and consumer confidence.
MPs were told in the House of Commons on Wednesday that the inquiry had begun, led by top Treasury civil servant James Bowler and with the "full support of the chancellor".
In the run up to the Budget announcement last Wednesday, leaks including the freezing of income tax thresholds, electric vehicle levies, and a tourist tax.
The BBC reports an OBR downgrade on UK productivity was also leaked.
Speaker Sir Lindsay Hoyle hit out at the leaks, branding it the "hokey-cokey Budget".
James Murray, chief secretary to the Treasury, told the Commons: "The government puts the utmost weight on Budget security, including prevention of leaks of information.
"A leak inquiry is now under way with the full support of the chancellor and the whole Treasury team."