While some Republicans have called on their candidate to focus more on inflation, far-Right influencers have said he should be more aggressive on immigration and crime.

Laura Loomer, a far-Right journalist, said “weak” surrogates were destroying the campaign, and warned Trump “needs to change FAST because we can’t talk about a stolen election for another 4 years”.

Candace Owens, another influencer, said a “MAGA civil war” had broken out, telling Trump: “I’m just not sure who is driving the MAGA bus any more. You’re losing that support from the people that believed in you … you need those people.”

This week, Democratic delegates will meet in Chicago for the party’s national convention, where they will hear speeches from Ms Harris, Mr Biden, Barack Obama and Bill Clinton.

Ms Harris will face opposition from up to 100,000 pro-Palestine protesters, who will hold mass demonstrations in the city against the Biden administration’s support for Israel.

Police have said the event will not be a repeat of the 1968 party convention, which was also held in Chicago and was derailed by Vietnam War protesters. Trump will campaign in Michigan, Pennsylvania and North Carolina during the convention.