THE SNP’s European election campaign has got off to a disastrous start after tens of thousands of personalised letters were sent to the wrong people.

The bungled mailshot was aimed at around 400,000 registered postal voters.

The party has now referred itself to the UK Information Commissioner’s Office (ICO) to see if there was a data breach.

Senior party figures blamed SNP HQ, which is run by Nicola Sturgeon’s husband Peter Murrell, for a mistake in the data given to mailing company Critiqom.

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Mr Murrell’s name appears on every letter as its official promoter.

The SNP later admitted there had been "a clerical error" in its office, and apologised to electors affected by the blunder.

The party also admitted it didn't know how many letters had been wrongly addressed. 

"Wer're looking into it," a spokesman said.

However one source estimated more than half the leaflets were "probably" affected.

Social media users posted pictures of A4 letters in windowed envelopes which had arrived at their house with someone else’s name as the addressee.

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Asked in 2016 if she would ever sack her husband as party chief executive, Ms Sturgeon told The Sunday Herald: "If I thought it was merited."

The problem emerged on Thursday, the day Ms Sturgeon launched the SNP’s campaign for the May 23 poll.

The letters, addressed to individual voters, began “Dear-”, and then had the wrong name.

Scottish LibDem leader Willie Rennie received a letter calling him "Edna".

One party insider said there appeared to have been “spreadsheet” problems, with small errors rippling across thousands of names and addresses.

The source said younger voters would probably brush off the problem, but the party was worried that older voters - those most likely to vote - would be annoyed.

“The problem is losing that personal touch older voters like,” the person said.

The Scottish Tories claimed one woman in the Berwickshire, Roxburgh and Selkirk seat received 30 SNP letters to her home – not one of them with her name on.

Tory MSP Murdo Fraser said: “The SNP has become so incompetent it can’t even carry out a simple mailing exercise.

“No wonder people are losing their faith that the hapless nationalists can govern a country.

“No sooner has Nicola Sturgeon declared a climate emergency than she ensures hundreds of trees die in vain.

“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.

“The SNP should apologise immediately, and refer itself to the Information Commissioner.”

Labour MSP Neil Findlay said: "This is an embarrassing blunder from the SNP. No wonder our public services are in such a mess when they can't even post a letter properly.

"This incident may have resulted in individuals' personal data being passed on to strangers.

"The SNP should apologise to all those affected by this blunder."

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An SNP spokesperson said: "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.

"We wish to apologise to the electors affected.”

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An ICO spokesperson said: “We have been made aware by the Scottish National Party of an incident relating to election materials and will be making enquiries.”

Critiqom said it expected the SNP to issue further details on the error later.