The Scottish National party faces being fined for a breach of data protection laws after sending out tens of thousands of European election mailings to the wrong addresses.
The Information Commissioner’s Office confirmed on Friday morning that the SNP had referred itself for investigation after voters across Scotland received letters addressed to strangers or neighbours.
The ICO said it was investigating under stricter EU data protection regulations, which carry significant fines for privacy breaches.
The election letters were signed by the SNP leader, Nicola Sturgeon, and urged voters to back the party on 23 May. The wrong recipients included Monica Lennon, a Labour MSP, who did not recognise the person Sturgeon was addressing.
The Scottish Conservatives said one woman in the constituency of Berwickshire, Roxburgh and Selkirk received 30 letters at her home, all addressed to people who did not live there.
The ICO said: “We have been made aware by the Scottish National party of an incident relating to election materials and will be making inquiries.”
The SNP acknowledged the letters had been sent in error, but played down the significance of the data breach. A spokesman said the party had sent out 400,000 election letters but did not yet know how many were affected.
“On Thursday, mail arrived with some electors that had the wrong addressee name on the letter,. A clerical error has been identified in our office. We have been in touch with the ICO, but there is no ongoing issue with the integrity and security of data or any issue of identity theft,” he said, adding that the SNP wished to apologise to affected voters.
The error emerged on Thursday morning while Sturgeon was preparing for first minister’s questions at Holyrood, where she goaded Ruth Davidson, the Scottish Conservative leader, over a Tory election leaflet which failed to mention Europe but referred 15 times to Scottish independence.
Murdo Fraser, a Scottish Tory MSP, said: “This wasn’t just inconvenient and confusing for tens of thousands of householders. It’s a very serious data breach, and one that could land the party in all kinds of trouble.”
Pete Wildman, a representative for Scotland’s 15 electoral registration officers (EROs), stressed that the country’s electoral registers had not been compromised. It is understood EROs around Scotland had fielded calls from concerned voters.
“Political parties and campaigners are entitled to copies of the full electoral registers in order to contact voters with their campaign arguments,” said Wildman.
“We are aware that some householders across Scotland have received election communications from a political party which are addressed to another person and are now concerned that the registration details for their address are inaccurate.
“We want to reassure voters that this problem is due to an error by that political party and not because of any problems with the electoral registers which we are confident are accurate.”