The UK rom-com king stars in a new animated adventure. By Sarah Theeboom

The Pirates! Band of Misfits is your first time voice-acting in an animated film. How was that experience?
It was truly an honour because I’ve watched Aardman Animations’ films all my life and adored them. My biggest fear was that I was going to screw it up.

Has that fear been allayed?
Now that I’ve seen the film, it has. But I like to live with a lot of fear; it gets me up in the morning.

Then you might make a good buccaneer.
I’m not sure that I would, actually. I can’t even travel in a car for five minutes without puking, so the idea of being on a ship for a long period of time is unthinkable.

Was voicing a pirate more fun than playing the Prime Minister in Love Actually?
The Prime Minister was rather a frightening part as I recall because I had to dance – and I hated that. But in a cartoon, the animators – especially if they’re geniuses like they are at Aardman – do 90 percent of the performance for you.

What was it like having Aardman co-founder Peter Lord in the studio directing you?
Because the stop-animation process is so painstaking and slow and finickety, I found [Lord] to be incredibly finickety as well. I’m accustomed to doing eight takes maximum – and we would do 28 takes. So I did want to cosh him for the first few sessions but I have now learned to love him.

In his production blog, Lord wrote: “There are always embarrassing moments when you realise that, for example, you’ve asked Hugh Grant to read the line ‘and?’ in excess of 40 times.”
Yes, I gave him a hard time for that. But, as I say, if you are the kind of person who’s accustomed to moving a character’s moustache 24 times for each second of film, your attention to detail is not entirely normal.

Did you get to see your character before you voiced him?
Oh yes – and it was slightly alarming because he was so physically different from me. There’s a habit in a lot of animated films nowadays, especially Hollywood ones, of making the character look a little bit like the actor. But Aardman is old-school, and they just design the character as they think is best and then they get someone to play it. So I was confronted with this big barrel-chested, bearded pirate who couldn’t look less like me. I had to actually do some acting to produce a voice that matched.

Did you get any mementos from the set?
I have to say, no-one’s given me anything and I’m rather bitter about it. The trouble is they might make a sequel, so they need all the puppets. But I did have something like 175 different mouths, after all. Just one mouth would be nice.

The film is very British. My favourite scene is when your character is dunking a biscuit in a cup of tea and the biscuit breaks in half and falls into the tea.
Yes, quite. And I think it’s a custard cream as well.

Do you think that will translate outside of the UK?
Well, that joke may struggle. But the thing is, Aardman – or Peter Lord at least – has the attitude that to give something an international appeal, you actually make it as local as you possibly can. The most disastrous thing you can do is try to cater to an international audience; just do what you think is funny and people will find it strangely charming.

As a child, did you ever dream of becoming a pirate?
That was never my fantasy. I really wanted to be in the US Cavalry and I still haven’t entirely given up hope.

The Pirates! Band of Misfits opens on July 26.