Katherine on Deep Throat, Extras and Graham...

Your CV says you starred in something called Deep Throat Live on Stage. Was this in a particularly desperate time of your career? Anything to pay the bills?
(Fits of giggles) I think that should come off the CV. That sounds so much saucier
than it actually was. The thing was, it didn't do what it said on the tin, and I
think people came to see it thinking that there'd be some sexy girl doing saucy stuff.
And I did a comic turn, I was on roller skates, and deliberately not being sexy. These
poor men at midnight during the Edinburgh Fringe wanting to get a bit of eye candy, and instead I was just falling all over the stage being a bit of a dick.

You've got a regular role on the ITV comedy drama Doc Martin. That must've been a great thrill, landing a regular job for a large chunk of the year?
It's brilliant, so brilliant. It's in a beautiful, beautiful part of the world. When you work it's a joy, and when you don't work you're in this amazing place. I've never felt so well, physically. You eat lots of fish, and I gave up smoking. And Martin Clunes, I've been such a big fan of his in everything that he's done that it was kind of a dream come true, that job. Also my brother was getting married in Cornwall, and I was the bridesmaid, so it was very convenient. It's a really nice job. And Martin is just about the funniest person I've ever met. He's so quick-witted, he's so funny, that I was embarrassed at how much I was laughing all the time.

Was it always your goal to get into TV?
If you're doing fringe theatre, which was what I was doing, not that many people are seeing it, and I felt like I was going round in circles. To get a big role you need a high profile. Even the West End shows and the RSC are necessarily going to go for the
more commercial casting choice, and I just wasn't that. So I knew that I had to have a
profile from TV just to get the theatre parts I'd want to do. Plus, I think a lot of TV
is brilliant nowadays, particularly a lot of comedy. The proper comedy is going on on
telly, not in the theatres.

Speaking of which, you had a part in Extras, didn't you?
I did. I had a tiny role. I had one line in that. But I thought it was very funny.

Do you want to stick with comedy or do serious roles as well?
If you asked me which actresses I really admire, it would be ones like Alison Steadman, Kathy Burke and Jessica Stevenson, and they're actresses with comedic bents, but they're also actresses who can do brilliant serious roles. I think I'd be really disappointed if I thought I was never going to get the opportunity to play utterly straight roles as well. But I wouldn't want to bite the hand that feeds me, so comedy's fine for me at the moment.