The Office for Budget Responsibility (OBR) has come under fire after announcing it will not inform the public when it provides the Government with economic forecasts.

Britain’s fiscal watchdog said this week it would not publish the timings of its forecast rounds ahead of March’s Spring Statement in an attempt to prevent speculation about the contents of its reports.

However, the move was criticised by investors and economists, who said it would reduce transparency at a time when the public finances are under close scrutiny.

In recent years, the OBR has revealed the dates on which it hands the Treasury evaluations of the economy, public finances and assessments of government policies in the run-up to fiscal events such as Budgets.

Economists have used these timetables to estimate how much breathing room the Chancellor is likely to have to balance the books, because the forecasts are informed by the state of borrowing costs at the time.

But on Monday, the OBR said it would keep these dates secret until the Spring Statement, following a National Cyber Security Centre’s review of its security processes after it leaked the November Budget.

Richard Hughes was forced to resign as OBR chairman over the damaging leak, which the organisation described as the worst failure in its 15-year history.

Future decisions on the transparency of OBR forecasts, including the Budget later this year, are also undergoing a review.

Mr Hughes said last month that the fiscal watchdog had taken the decision to publish its timetable for its forecasts ahead of last year’s autumn Budget “out of a desire for transparency and accountability”.

However, he told the House of Lords economic affairs committee last month that this “has provided a set of hooks for journalists to ask questions”.

“How we have got into a world where those questions are suddenly being answered, or at least speculated about by some people, I do not know.”

There are fears that the change to not publish the timings of the OBR’s forecast rounds ahead of the Spring Statement will decrease transparency and cause concern for markets.

James Athey, a fund manager at Marlborough, said: “Investors would prefer not to be going down the route of less transparency.”

He added that “dramatic shifts” between the fiscal statement in March last year and the Budget in November had caused financial markets to pay closer attention to OBR forecasts.

“Obviously, it couldn’t have come at a worse time to have such a focus on this whole process anyway.”

The growing scrutiny follows the fiscal watchdog accidentally releasing its official forecast 45 minutes early, before the Chancellor had finished delivering her Budget on Nov 26.

This week, it emerged that the OBR document had been downloaded almost 25,000 times before the Budget.

There are worries that changes to how the fiscal watchdog operates will reduce visibility of the fiscal risks facing the UK.

Jagjit Chadha, a Cambridge University economics professor, said the changes “seem to be a move back from best practice”.

“I think it’s rocking the foundation of it unnecessarily. I’d rather maintain transparency.”

He added that the move was unlikely to directly affect borrowing costs but warned that it came at a time when rising political uncertainty could cause fluctuations in the bond market.

He said: “If we are in a problematic situation come March or later in the year, as we head to the second forecast of the year, what that’s likely to do then is interact with the level of political uncertainty, which may become heightened after the elections in May, and cause further volatility in bond market prices.”

The OBR was contacted for comment.

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