The 1950s-set drama focuses on a news crew headed by producer Bel Rowley (Romola Garai), debonaire news host Hector Madden (Dominic West) and home affairs reporter Freddie Lyon (Whishaw).
Whishaw told What's On TV: "[Freddie is] a brilliantly well-drawn character, I think. He got himself a good education but has definite issues with class and authority. He's always bucking against authority."
Whishaw promised that facets of Freddie's past will be revealed gradually throughout the show's six-part run.
"The pieces start to come together and you start to get a glimpse of what his anger is about," he said. "You discover why he's angry at privilege and why he's angry with the government."
The Brideshead Revisited star also claimed that he is "very pleased" with the murder plot at the centre of The Hour.
"It made me want to carry on watching, which is important," he said.
The Hour begins on Tuesday, July 19 at 9pm on BBC Two.
> The Hour: Episode one in pictures
Watch the trailer for The Hour below: