Anthony Head plays Ed Walker...

Why do you think viewers took the first series to heart?

It struck a chord right across the board because it's all about warmth. That doesn't mean it's old-fashioned - it just means that viewers empathise with these characters. They are drawn to Lauren and Ed. Their relationship is very attractive because they really love each other.

Series 2 is coming up. Has the tone of the show altered at all?

It's still really funny, but I think that this time the characters are even richer. They have learnt from what happened last year and really grown. They've given themselves more freedom.

The producers have also added something: they are not afraid to have moments of poignancy. That's a brave thing to do, but I think we've pulled it off. It also adds to the drama because it allows you to see a little more into Ed and Lauren's relationship.

Why do viewers like Ed and Lauren so much?

People love to spend time with Ed and Lauren because they are an example of what a relationship should be like. What they have is what we all want in a relationship. They don't care about age - they simply bring out the best in each other. And, most importantly, they genuinely love each other. That's why audiences are drawn to these two wonderful characters.

What new do we find out about Ed in the second series?

We discover why he's such a control freak. It turns out that his mother [Rose, played by Honor Blackman] spent a lot of Ed's childhood travelling without him and his brother Alan. The model we came up with was Kate Winslet's character in the movie Hideous Kinky. She was a wonderfully free-spirited mother who travelled the world, but maybe her children felt neglected.

What effect did that upbringing have on Ed?

It meant that Ed had to bring Alan up. That puts the brothers' relationship into perspective and explains why Ed suffers that annoying, bumbling but lovable idiot of a brother. He has a very soft spot for Alan because he's always been responsible for him. It's interesting that Ed is the product of that upbringing. It's turned him into someone much more structured. But it also makes sense that he should be attracted to Lauren, because she's a free spirit and so different from him.

Have you enjoyed working with Eve Myles?

Absolutely. We really do get on. When you're working with other actors, you sometimes have to say, 'I don't want to take you by surprise, but I'm thinking of doing this in the next scene'. I never have to say that to Eve because we have such an intuitive understanding of each other. We never have to say to each other in advance how we're going to play a scene - it just happens naturally.

Do you think that enhances the show?

Definitely. I think viewers can see that Eve and I really hit it off. That's another reason why the show has struck such a marvellous chord with audiences.