However, as his overall poll numbers plummet, it will be the loss of support from evangelical Christians - a cornerstone of Republican presidential campaigns - that will be of particular concern to the embattled Trump camp.

According to a Reuters/Ipsos opinion poll, Mr Trump had only a 1-point edge over Hillary Clinton among people who identified as evangelicals, down from a massive 12-point advantage for the Republican in July.

Christianity Today, a leading evangelical magazine, said in an editorial that Christians should not support a man whose life is based around “idolatry, greed, and sexual immorality”.

“The revelations of the past week of his vile and crude boasting about sexual conquest — indeed, sexual assault — might have been shocking, but they should have surprised no one,” wrote Andy Crouch, editorial director.