STATISTICS regulators have scolded the National Records of Scotland for a lack of transparency over fixing the census fiasco.

Scotland’s census, delayed a year due to the pandemic, was extended at great expense to taxpayers following a poor response rate.

Against a 94 per cent target, only 87.9% of households returned the document, despite the threat of prosecution and several extensions to the deadline.

The Scottish Government was forced to extend the deadline past the original May 1 date, which allowed around 200,000 extra households, or 8.7%, to complete the document.

An original budget of £10m for the extension has now been revised to around £6m - taking the total costs for the project to £148m.

This morning, Constitution Secretary Angus Robertson will give evidence to Holyrood’s Constitution, Europe and External Affairs Committee about the census after the minister branded the low response rate as a “good level” of data.

The registrar general and the director of statistical services of NRS will also be grilled by MSPs.

In a letter to Pete Whitehouse of National Records of Scotland, Mark Pont from the Office for Statistics Regulation has warned that “it would be in NRS’s interests to be more transparent” about “the steps hat it is taking to generate good quality census estimates”.

He added: “We consider that being transparent about the various current activities, plans, processes etc would assure users of NRS’s trustworthiness and reassure users that they can confidently expect high quality estimates from the 2022 census.

“Various practices within the code of practice reinforce this need for openness even ahead of the release of the statistics.

“Demonstrating this trustworthiness is especially vital given the importance of census estimates.”

Mr Pont has called on NRS to “update the existing materials soon” in order how to “reflect how you are adapting your processes and the possible impact on the expected quality of census estimates”.

He added: “We are mindful of the need to be proportionate in doing this, especially when the focus of your team is on processing census data.

“At the very least we expect a clear description of how the various steps you are taking help to assure the quality of census estimates fit together, and to provide updates to users about the level of quality that they may expect from census outputs.”

A spokesperson for NRS said: “NRS continues to welcome OSR’s support and guidance as we deliver Scotland’s census.

“We have recently made available on the Scotland’s census website details of the international steering group discussions, and a paper on the evolving census design.”