Prince Harry and Meghan Markle's popularity has slumped to an all-time low in the US, where they are now less popular than the disgraced Prince Andrew, a shock poll has found. 

Since December last year, Harry has sunk 48 points and Meghan 40, giving them net approval ratings of -10 and -17 respectively, according to a survey by Redfield & Wilton for Newsweek, conducted on February 19. 

While Andrew is still viewed negatively following his New York civil trial against his sex accuser Virginia Roberts - which he settled out of court - his net approval rating sits at -2, with 26 per cent of Americans saying they like him compared to 28 per cent who do not. 

The Sussexes' nosediving popularity across the pond comes just days after they were royally mocked by South Park - a satirical cartoon famed for having its finger on the pulse of American culture. 

The couple were lampooned in an episode aired on February 15 - four days before the latest poll - which was entitled The Worldwide Privacy Tour and depicted them embarking on a publicity blitz to promote the Prince's new book, Waaagh.