A claim that Scotland has a quarter of Europe’s potential offshore wind resource was always “poorly constructed”, the UK Statistics Authority (UKSA) has found.
Scottish ministers have already admitted that the claim was “out of date”, after opponents put it under scrutiny recently.
However, the regulator has said the 2010 publication it was based on gave an “inflated” picture of Scotland’s potential wind resource compared to the rest of Europe.
It has written to the SNP to emphasise the importance of using quantitative evidence appropriately.
Several figures in the party, including Nicola Sturgeon and John Swinney, have repeated the claim that Scotland has 25% of Europe’s potential offshore wind resources in various forums.
UKSA chairman Sir Robert Chote said: “In summary, the calculation for Europe’s offshore wind potential was much more restrictive than that for Scotland.
“So, when the figures are used together, they give an inflated picture of Scotland’s potential relative to the rest of Europe.
“We understand that Scottish Government and ministers are already aware that this 25% figure is inaccurate.
“On 15 November, the Minister for Green Skills, Circular Economy and Biodiversity, Lorna Slater, acknowledged in Holyrood that the figure was outdated, but not that it was poorly constructed.
“It is good practice for elected representatives to correct their use of official statistics.
“My office is engaging with the Scottish National Party about its ongoing use of the claim and with the offices of those who have recently used it to emphasise the importance of using quantitative evidence appropriately.”
Scottish Liberal Democrat leader Alex Cole-Hamilton had earlier written to the UKSA about the use of the 25% figure.
He said: “Green minister Lorna Slater and Government spokespeople refused to confirm that the claim had always been bogus, instead claiming that it is merely out of date.
“This spin has now been dismantled by the highest statistical authority in the land.
“I fully support the expansion of Scotland’s renewable sector but the strong case is undermined when the Scottish Government and SNP use figures which leave them open to the charge of misleading and misrepresenting.”
Cole-Hamilton also raised the issue as a point of order in Holyrood on Thursday, saying the “fictitious” figure still appeared on SNP leaflets.
Presiding Officer Alison Johnstone said it was of “paramount importance” that truthful information is provided to Parliament and any errors are corrected at the earliest opportunity.
Nicola Sturgeon then raised a further point of order, where she said the figure is “no longer appropriate to use because it is out of date”.
She said Lib Dem politicians have also used the statistic in the past.
In a third point of order, Cole-Hamilton said she had not addressed the issue of the statistic’s accuracy and accused her of an unfair “broadside” against him.
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