Ant & Dec
Ant & Dec is the collective professional name for the entertainment act comprised by Declan Donnelly and Anthony McPartlin. Throughout the 2000s they had a highly-rated Saturday-night ITV show, called Saturday Night Takeaway which was the initial competition for the BBC Wales version of Doctor Who. An early sign of the strength of the revitalised Doctor Who was the fact that it trounced Ant & Dec in the ratings, breaking the three-year hold that Ant & Dec had on Saturday night audiences.
Years later, they were involved in the National Television Awards Sketch 2011.
NTA sketch
In the sketch, Ant & Dec knew the Eleventh Doctor. Ant and Dec had been bound in invisible space handcuffs and needed the Doctor to release them. Dermot O'Leary had to inform them that the Doctor was a little too busy to free them.
Like other celebrities in the tongue-in-cheek sketch, it's difficult to say that Ant & Dec are actually a part of the DWU. However, the precise nature of their appearance — and the fact that the Doctor won't free them — can be read as a metaphor for for the fact that 'Doctor Who had effectively "shackled" Ant & Dec by displacing them from the top of the Saturday night ratings heap.