OBR says Budget leak 'worst failure' in its history

The Office for Budget Responsibility (OBR) has said the early publication of a key Budget document was the worst failure in its 15-year history but it was inadvertent.

The UK's official forecaster confirmed the market-sensitive report was accessed 43 times from 32 different computers in the hour before the chancellor's speech.

OBR chairman Richard Hughes called in a leading cyber-security expert to investigate how the crucial document was put on its website too early.

At the time, Mr Hughes said he was "personally mortified" by the mistake and acknowledged the "deep disruption" it caused.

On Monday its report into the mishap concluded it had "inflicted heavy damage on the OBR's reputation".

"It is the worst failure in the 15-year history of the OBR," the report said.

It added: "It was seriously disruptive to the Chancellor, who had every right to expect that the EFO (economic and fiscal outlook) would not be publicly available until she sat down at the end of her Budget speech, when it should, as is usual, have been published alongside the Treasury's explanatory Red Book."

Chancellor Rachel Reeves's Budget was thrown into chaos when the OBR's forecast - which contained the measures she was about to announce - was discovered online.

The OBR assesses the health of the UK's economy. It is independent of the government but works closely with the Treasury.

Its reports are released alongside big government events such as the Budget.

Details of the Budget are supposed to be kept under wraps until the chancellor announces them in the House of Commons, due to them being market-sensitive.

But early publication of the OBR's report effectively confirmed a number of new measures, including a pay-per-mile charge on electric vehicles, and a three-year freeze on income tax and National Insurance thresholds.

The OBR quickly removed the forecast document from its website and apologised for the release, which it blamed on a "technical error".