The presenting duo, who on Wednesday (January 25) picked up their 11th National Television Award, said that Simon Cowell, Alesha Dixon, David Walliams and Amanda Holden have "instantly clicked".
"The new panel is the best we've ever had," they told the Daily Star. "It all just works, they instantly clicked.
"It's great to have Simon back. He's fired up and more harsh than ever. He knows he wants to find a huge star so he's not messing around. He just says to them, 'No, you're not a star'. David is hilarious, he constantly winds Simon up."
The I'm a Celebrity pair similarly told Digital Spy at the NTAs that they considered Cowell to be "the best talent show judge in the world".
"He's upped the stakes this year," they claimed. "He's not giving an inch. He's given us all a tough time."
Dec also revealed today that Cowell is considering hiring guest judges while Holden recovers from the life-threatening birth of her daughter Hollie this week.
> Britain's Got Talent panel have 'instant rapport' at first auditions
Watch Ant & Dec discuss the new Britain's Got Talent with Digital Spy below: