Hugh is appearing in upcoming Twenty Twelve follow up, W1A, which this time pokes fun at the management of the BBC.
Comparing the ITV and BBC shows, he said: “They’re both punishing days when you’re on the set, but with Downton, the pace is a bit steadier, because it’s a much bigger sort of machine and we don’t shoot as much material each day.
“Twenty Twelve and W1A are quite frenetic in their pace and the page count is quite a lot. The nature of filming is very different – one is faux documentary style and the other couldn’t be more sort of classical.
“I love the fact that there is that variety.”
Of his two well-known characters, he said: “I suppose Lord Grantham and Ian Fletcher are basically both just trying to run a big team and hoping that the wheels don’t fall off the vehicle.
“Yeah, that’s a fair comparison. They’re both men trying to get by.”
Hugh recently appeared in World War II movie The Monuments Men, alongside George Clooney, John Goodman, Bill Murray, Matt Damon, Jean DuJardin and Cate Blanchett.
He said: “I was fantastically nervous working with these great icons of the screen.
“Of course, as soon as you get on set with them, you realise they’re just actors who want to do a good job too.”
W1A starts on BBC2 on Wednesday 19 March.