As another spectacular year of Doctor Who draws to a close, we catch up with Russell T Davies, Julie Gardner and Phil Collinson.

Find out what they had to say about dubs, duvets and Donna.

What's been the hardest part of your job this year? And the main thing that's made it all worthwhile?

JG: Sometimes the hardest thing is sustaining the sheer volume of workload. Sometimes Russell and I have sacks of rushes to watch across Doctor Who, Torchwood and The Sarah Jane Adventures. Then, when you get into the post production period of fine cuts and mixes but you're still working on scripts with writers and doing tone meetings in prep, the diary can seem wildly stretched.

Even when it's the hardest, the work is always fun and challenging and rewarding. I work with the best people in the industry. It's a privilege to be around them. It's always worthwhile when we sit in a final mix (the moment we complete the music and sound dub) and see a finished episode for the first time. I never stop being excited by the work.

You, Russell and Phil always seem to have a ball recording the commentaries. Are all your meeting as crazy as those?

JG: The three of us have worked closely with each other for over four years so now know each other really well. We've got a great shorthand, built over years of working long hours, laughing a lot and pushing each other to do better work. We can wind each other up so we're like cackling kids.

With three successful series of Doctor Who under your belt, how are you going to raise the bar yet again for Series Four?

JG: All the time it's about telling the best stories we can. If great scripts are well cast, directed and produced, anything is possible. Catherine Tate is extraordinary as Donna. It's a joy to see her in action. Just wait! And Kylie Minogue is on The Titanic! Oh it's all exciting... And every department is ambitious to do their best work yet. I can promise you many surprises to come...

What's the difference between writing a Christmas Special compared to writing a regular Doctor Who episode?

RTD: No massive difference. Every episode of Doctor Who is different, so every episode throws up its own peculiar challenges anyway.

Was it always an ambition of yours to get Kylie to appear on Doctor Who? Who approached who?

RTD: It was never an ambition cos I never thought it would be remotely possible! Kylie's Creative Director, Will Baker, first suggested it, and we chased things from there. But I still didn't believe we'd get her, until she actually turned up on set!

Was the return of Donna something you'd considered as far back as The Runaway Bride?

RTD: I always wanted her return in some shape or form – we certainly would have approached Catherine at some point in Series Four anyway, just for a guest appearance. Again, like Kylie, I never thought she'd have the time! So to get a full series commitment was just astonishing, and a miracle, and it's been a joy.

What were the biggest challenges in creating a 'disaster movie' on a TV budget?

PC: Russell delivered a brilliant and ambitious script and I think we've achieved 95 per cent of what he originally planned. Some sequences were cut or trimmed to fit the budget - but only after we'd exhausted trying to achieve them. As always I think the most important thing is to know your limitations and stick to them - that way you are sure to deliver something polished and exciting.

In what ways did the media interest around Kylie affect the making of Voyage Of The Damned?

PC: We had to provide a little more security than usual, to make sure she was safe, but other than that it was business as usual. Luckily most of the action takes place indoors, so we were able to operate quite smoothly.

What can you tell us about the recent filming in Italy, and how that came about?

PC: I knew before we began filming Series Four that an overseas shoot was needed to achieve exterior scenes for an episode set in Pompeii on eruption day. There are standing replicas of ancient roman cities in Malta, Bulgaria and at Cinnicitta studios in Rome and we considered using all three.

The Cinnicitta sets are the most recently built (constructed for HBO's ROME in 2004) and the biggest and so were the most appealing to us. The organisation of an overseas shoot is tricky and so Tracie Simpson and myself spent most of blocks 1, 2 and 3 planning the trip, as well as filming other episodes. I'm really pleased with the footage we shot there and it was well worth the angst.

If you had a Sonic Screwdriver what would be the first thing you'd use it for?

RTD: To fix my lousy Cardiff broadband connection.

JG: Surely it could help change duvets...

What's the most unusual thing you've had to do in the name of Doctor Who this year?

RTD: I autographed a baby.

JG: Getting David Tennant to Blackpool in time to switch on the Illuminations was a bit of a number... Singing Amy Winehouse's Rehab with Phil Collinson on video wasn't our finest moment.

If you could job swap with anyone on Doctor Who, who would you swap with?

RTD: Steven Moffat. I'd love to see inside his mind! Oh, the labyrinths of neural connections! All made of gold!

JG: I'd like to be Russell T Davies on a great writing day. Imagine being in his imagination! Or I'd be David Tennant at the controls of the TARDIS. Or else I'd be Murray Gold when he writes Donna's theme for Series Four.