A woman has alleged that Doug Emhoff slapped her during an argument when they were a couple in 2012, before he married Kamala Harris, and the accusation has prompted a spokesperson for the second gentleman to issue a denial.

The woman has not publicly identified herself. She first spoke to the Daily Mail anonymously and then again after Emhoff’s denial, on the condition that her name was not disclosed. The tabloid described her as a successful lawyer in New York and published pictures of the then couple, but with her face blurred out.

She alleges that Emhoff struck her so hard while they were attending the Cannes film festival in France in 2012 that the force of the slap spun her around.

The allegations were described as “untrue” by a spokesperson for Emhoff, speaking to Semafor, as reported by CNN, who added that “any suggestion that he would or has ever hit a woman is false”.

The Daily Mail has cited three unnamed friends of the woman backing up her account and she has now accused Emhoff of hypocrisy. The woman had not given interviews herself until this week, when she spoke with the Daily Mail.

The woman also criticized what she saw as Emhoff’s burnishing of his reputation as a “perfect” spouse and a feminist, standing alongside Harris, the Democratic party nominee for president who will be the first female president of the US if she wins against Donald Trump next month.

“He’s being held out to be the antithesis of who he actually is. And that is utterly shocking,” she told the Mail.

Meanwhile, Trump’s election campaign has been pointing to the allegations against Emhoff as it fights back against damage to the Republican nominee’s reputation from a civil verdict against him that he sexually abused writer E Jean Carroll and serial allegations from dozens of women that he has sexually assaulted them, all of which he has denied.

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