Kamala Harris’s allies have rallied to her defence after Joe Biden’s challenger from within the Democratic Party suggested the vice-president was not up to the job.

Dean Phillips, a Minnesota congressman who has launched a campaign to challenge President Biden for the party’s nomination, drew angry rebukes after he claimed voters and Ms Harris’s own circle had no confidence in her.

Mr Phillips told The Atlantic that “Americans have made the decision” the 59-year-old was not prepared in the event she needed to “step into” Mr Biden’s shoes.

He added: “That is not my opinion.” However, Mr Phillips said he had heard “from others who know her a lot better than I do that many think she’s not well positioned”.

“She is not well prepared, doesn’t have the right disposition and the right competencies to execute that office,” he said.

Christina Reynolds, an ally of Ms Harris who served in the Obama administration, accused Mr Phillips of “falling back on a tired and sexist old trope”.

“I’ve gotten to see her up close,” she told The Telegraph, “so I feel very comfortable saying not only does she have the disposition to do this job, she is doing a phenomenal job of it”.

‘Scoring cheap political points’

Karen Finney, a prominent Democratic strategist and close friend of Ms Harris, demanded that Mr Phillips apologise.

“Hiding behind the well-worn ‘people are saying’ and leaning in to gossip over your own experience for the sake of scoring cheap political points is not leadership,” she said.

Ms Harris’s office declined to respond to the comments when contacted by The Telegraph.

However, insiders in her team have pointed to the claims of racism and sexism in some of the criticism around the vice-president.

Tina Smith, a senator from Mr Phillips’s home state, said: “I know the vice-president well and know her to be exceptional.”

Ms Smith described the vice-president as “always prepared” and “deeply knowledgeable”, adding – in a pointed aside – that she was also “loyal”.

Mr Phillips, 54, launched his long-shot bid against Mr Biden, 81, a month ago, saying the US president’s age and poor polling had become an “emergency”.

He pointed out that Ms Harris’s polling was even worse, in his interview with The Atlantic on Tuesday. “It’s pretty clear that she’s not somebody people have faith in,” Mr Phillips said.

‘I can handle weaklings like Trump’

His late entry to the race has triggered fury from Democrats, who argue that it is too late to block Mr Biden winning the party’s nomination but could severely damage his re-election bid.

Mr Phillips’s bid comes as he faces his own threat of a Democratic primary challenge for his Minnesota district should he seek re-election to Congress.

His wide-ranging interview with The Atlantic was tinged with derision at times, with Mr Phillips at one point claiming he had looked into Donald Trump’s eyes “for the better part of an hour”.

“I know exactly how to handle weaklings like Donald Trump,” Mr Phillips said, but he declined to reveal his strategy. “Why would I give away my special sauce?” he added.

The magazine wryly noted Mr Phillips must first dispatch the incumbent president “before he can douse Trump with his proprietary Dean Sauce”.