The Office for National Statistics has announced that Government ministers, civil servants and special advisors will no longer be given access to official data 24 hours before its is published.
John Pullinger, the National Statistician, announced that from 1 July the practice of "pre-release" will end.
The move brings to an end a system that has long been criticised by experts as serving no legitimate governmental function and running the perennial risk of market-sensitive data leaking.
The UK Statistics Authority (UKSA), which oversees the ONS and polices the misuse of statistics, is forced to issue regular reprimands to government departments for breaking rules on the handling of such data.
More than 100 people in government currently receive data on unemployment early.
There have also been long-standing suspicions that some in financial markets might be trading on such information before it has been released.
In a letter to Sir David Norgrove, the new chair of UKSA, Mr Pullinger said efforts put in place in March to strengthen controls on data after a review begun late last year "are not successfully dealing with the risks the review sought to mitigate".
He said: "On the basis of all the information now available to me I consider that the public benefit likely to result from pre-release access to ONS statistics is outweighed by the detriment to public trust in those statistics likely to result from such access".
Before the general election, a letter to The Times, signed by 114 academics and experts, called for pre-release to be ended.
It said: "This outdated and unnecessary practice is detrimental to public trust in official statistics, as the UK Statistics Authority has noted. It can (and does) result in serving government ministers having access, in parliamentary and election debates, to information which is unavailable to their opposition counterparts. In addition, the higher the number of people with pre-release access, the greater the risk that information, including market-moving data, might leak."
The signatories included the former National Statistician, Jil Matheson, and the ex-chair of UKSA, Sir Michael Scholar.
Sir Andrew Dilnot, who was the head of UKSA until April, told The Independent in 2012 that the practice of pre-release should be scrapped, specifically mentioning the risk of insider trading.
Given the long-standing opposition of UKSA to pre-release the decision, only now, of the ONS to end it will raise questions.
A spokesperson for the ONS told The Independent on Thursday that the accumulation of public concern and a hardening of the recommendations of UKSA earlier this year had finally persuaded it to act.
The spokesperson also said that attempts to persuade ministers to considerably reduce the number of officials on the pre-release lists had failed.
"The longstanding opposition of the UK Statistics Authority to the practice of pre-release access is well known," they said.
"Several exercises in recent years have succeeded in limiting the numbers of people across government with access. The most recent of these began in December 2016. However the National Statistician remains concerned about the extent of access remaining and its effect on public trust in official statistics".
Hetan Shah, the executive director of the Royal Statistical Society (RSS), which organised the Times letter, welcomed the move.
"It’s a major achievement for the RSS and our members. It will reduce the opportunities for figures to be ‘spun’ and increase public confidence in official statistics. It will also lower the risk of market-sensitive information being leaked or abused."
In 2011 the Office for National Statistics (ONS) investigated rumours that data showing an unexpected drop in inflation had been circulating in the markets before the official release time. The ONS has always declined to comment on the outcome of that investigation.Reuse content