A government minister has reported Boris Johnson to Britain's data watchdog suggesting his use of her contact details was "not kosher".
Harriet Baldwin, who is supporting rival Jeremy Hunt in the leadership race, claimed her email address was "dug out of a very old email list" from when she supported Mr Johnson's re-election bid for mayor of London in 2012.
The Foreign Office minister said: "It struck me as being really off. It's obviously just some spam from some old database.
"Just proactively emailing in that way is not kosher these days."
Ms Baldwin has asked the Information Commissioner's Office to investigate if Mr Johnson's use of data was legal after she, her husband, a relative and friend all received emails from his campaign asking for support - despite not having opted in to receive such information.
According to ICO guidelines, any candidate wishing to send emails, texts or make automated calls "must ensure that they have consent from the individuals to use such marketing channels".
Ben Howlett, former Tory MP for Bath said he was called "by a member of the Boris campaign team" to ask who he was backing.
Mr Howlett, who is not supporting Mr Johnson, said the contact was a "potential serious breach" of GDPR and called for a "full review" as a "matter of urgency".
Since posting about the call on social media, the former Bath MP, who chairs a campaign to improve public trust in companies' use of personal data, said "dozens" of other members and councillors has got in touch to say they had been "contacted without signing up".
MP David Morris, who is supporting Boris Johnson's rival Jeremy Hunt, told BuzzFeed News: "It's deeply troubling that foul play may be afoot in this contest. "I urge ICO to look into all alleged breaches so that we can be sure the contest is being conducted within the rules."
An ICO spokeswoman told the Mirror: ”We are aware of these concerns and will be assessing the information provided.”
A Campaign source said: "The BackBoris campaign is compliant with GDPR and the Data Protection Act."
