SNP bosses were forced to apologise after European election mail shots were sent out with the wrong addresses - with Scottish Lib Dems leader Willie Rennie receiving one addressed to 'Edna'.
Nicola Sturgeon's said "some" of the 400,000 letters sent had the wrong name on them as a result of a "clerical error".
Mr Rennie posted a picture of a letter addressed to "Edna Rennie" on Twitter. He said: "I will insist that Nicola Sturgeon addresses me as Edna in the Scottish Parliament
Labour and the Conservatives raised concerns of a possible data breach.
The Tories said one woman in the Berwickshire, Roxburgh and Selkirk constituency had received 30 letters to her home - but that not one of them had the right name on.
Labour’s Monica Lennon also posted a picture of the letter, asking: "Who is George Mackie and why does @NicolaSturgeon think he lives in my house?"
Scottish Conservative MSP Murdo Fraser said: "The SNP has become so incompetent it can't even carry out a simple mailing exercise."
He added: "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."
Meanwhile 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.
An SNP spokesman 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."