What was your reaction when you first read the script?

It was actually at the read-through because the scripts were slightly unfinished. That's how Julia operates, the easel is always permanently in progress, as it were, so I never got to read the entire series until the actual read-through itself. That was slightly remarkable as obviously the material is very... what's the word? Exotic. So I was taken aback, because it doesn't pull any punches. But because I've worked with Julia before, it's no surprise whatsoever in that regard.

I remember at the read-through people's faces dropping in delight and amazement because it's a very clever tightrope walk between something that's disgraceful but never explicit - which is why it's such good fun to make and such good fun to watch.

As you say, you've worked with Julia before. What is it you like about the slightly twisted worlds she creates?

I worked with Julia on Hunderby, which is a very dark world. I like the sheer inventiveness... It's pretty Dickensian in its detail and naughtiness and, crucially, she allows characters to flourish and expose themselves in their full colour as opposed to permanently moving the plot along.

There's a lot of time for these characters to marinate in their environments and you sort of observe these fabulous creatures in these bell jars. That's what I like about Julia's work generally, it's intensely based on the characters and that just makes more entertaining viewing, really.

And what do you look for when choosing your roles?

I tend not to repeat roles I've played in the past. Sometimes you can't resist it because you need to earn some money and you need to be occupied, but I do try to avoid doing things I've done before. I love eccentricity and villainy, they're the two things I take great pleasure in performing as opposed to what I slightly churlishly call 'information in costume'.

How would you describe your character in Sally4Ever?

He is very much a victim of Julia's character's behaviour, but he also does bring it upon himself because he's a very... I don't want to say 'boring character', but he is boring! And it's very difficult for Catherine Shepherd's character to want to stay around him.

I suppose the best [comparison is] that brilliant movie Brief Encounter, where in some ways I'm the guy at home where, yes, I know it's boring, and conventional and safe, but actually it's something rather nice to return to after you've been through the maelstrom of being exposed to Julia's character, which is thrilling, it's exciting, it's a journey, but it exacts an incredibly high price.

You've got a great comedic cast on the series. Was it a fun set to be on or did everybody take it very seriously?

We all had totally, totally good fun. Julia's directing style - along with people like Armando Iannucci - creates a very, very fun atmosphere, so you can play and you can be naughty and silly and daft and invent, without thinking, 'oh god, I'm wasting lots of people's time and I'm misbehaving.'

You're encouraged to be inventive and imaginative with the material, so yes, it's a very, very fun place and at times it's difficult to get through the material in a competent and professional way.

There were scenes in the first week where I'd find myself corpsing because it is funny and I feel very guilty about that because you're not really there to enjoy it, it's for the audience to enjoy.

Nevertheless, it is just that funny. And I think Julia, if she doesn't feel she's on the verge of corpsing, as far as she's concerned the material isn't working.

What do you think the series says about love and relationships?

Generally speaking, it's about how we find fulfilment in the people we surround ourselves with. It's very exciting to be attracted to a world you've never occupied or that you've fantasied over. You think, I should go to the perimeters of my experience in the short space of time that we're on the Earth, but actually fulfilment in that regard is difficult to come by. Be careful what you wish for, because these Christmas decorations look fabulous from a distance but when you get closer you see a lot of flaws. The search for fulfilment is not straightforward.

What makes you laugh?

Things that are very serious, I think. That's what I Iove the most. Rows at stations... Disputes on the tube... Conflict makes me laugh as opposed to gags and wordplay and clever writing. That doesn't appeal to me particularly. I think some of the best comedy is basically drama just masquerading as comedy.

I also love eccentricity and peculiarity. Growing up I was very much taken by the world of the Carry On films, which I know splits people and could be described as sort of broad or crude but actually the characters in there, the performances, are what made me want to get into acting and the comedy world.