A change in the way government statistics are calculated has handed the chancellor a windfall of over £2 billion.

Revisions to data on government borrowing mean that the public sector current budget will benefit to the tune of around £350 million a year dating back to the 1998/99 financial year.

An error in the way spending on road maintenance is accounted for, which has now been corrected by the Office for National Statistics (ONS), has given Gordon Brown more leeway as he seeks to meet his "golden rule".

The rule states that the government will borrow only to invest over the economic cycle, and Brown had predicted he was on course to meet it with about £8 billion to spare.

With an election looming, the unexpected £2.1 billion windfall could give the chancellor greater leeway for tax or spending giveaways.

Alternatively, he may prefer to bank the extra billions and stress the prudence of government financial planning.

Trust in statistics

Opposition politicians have expressed concern at the timing of the move, though officials insist there has been no ministerial involvement in the decision.

And the move has prompted press criticism which could undermine public trust in government statistics.

The reclassification coincided with a report from the Statistics Commission on how key opinion formers view official data.

It found that the interviewees believed that the quality of UK official statistics is "up with the best in the world" but said there was still room for improvement.

There was a widely-held view that there needs to be greater distance between the producers of statistics and government, possibly with an independent regulatory body which would monitor the use of official statistics.

Chairman Professor David Rhind said: "This study seeks to determine what a group of some 36 leading opinion-formers actually believe about public trust in official statistics." 

"Insofar as there is perceived to be a problem, there is a problem.

"This research is primarily about understanding the nature of the problem and, as far as we can, its roots. 

"The interviews, undertaken on our behalf by MORI, buttress the need for still greater effort in planning the collection of statistics across all of government.

"They also point to the need for communication of statistics to be improved to give commentators, intermediaries and the public alike the confidence that UK official statistics are fit for purpose and can be trusted."

National statistician Len Cook said there were five priority areas that needed to be tackled.

There should be improved communication in all aspects of ONS work, and information should be made relevant to the general public.

He also backed assurances on the quality of data, reinforced independence for the ONS, and providing opportunities for the public and the media to improve their statistical skills.

Maastricht debt

Also released on Monday, figures on government borrowing showed that in the 2004 calendar year general government net borrowing was £35.8 billion.

This was fractionally down on the net borrowing of £35.9 billion in 2003.

The 2004 figure totalled some 3.1 per cent of gross domestic product, just above the European Union stability and growth pact limit of three per cent. However, it was down on the 3.3 per cent in 2003.

At the end of 2004 general government gross consolidated debt was £481.4 billion, equivalent to 41.6 per cent of GDP, compared with £437.4 billion at the end of 2003.

This is significantly below the EU reference point of 60 per cent for excessive debt.