Russell reveals Runaway Bride origins in DWM special.
Russell T Davies has explained the genesis of this year's Christmas Special in the pages of Doctor Who Magazine's Series Two Companion.
"The Runaway Bride was another of those ideas I'd had for ages, ever since the return of Doctor Who was first announced," he said.
"Then, at the BAFTA screening of The Parting of the Ways, Jane Tranter announced not just the 2005 Christmas Special, but another for 2006 as well (I swear, Julie Gardner had forgotten to tell me about the 2006 one - as Jane was on the microphone, Julie was watching my head explode. 'Oh yes, sorry, I knew there was something I meant to tell you...')
"And since we all knew that Billie would be leaving at the end of Series Two, and that I didn't want to introduce the new companion until the start of Series Three, then suddenly The Runaway Bride took on a whole new lease of life," he added.
"So the story was taken out of Series Two, elevated to Christmas, and the gap was filled by Tooth and Claw, which was bumped up to the second slot..."
More of Russell's behind-the-scenes scoops, plus a comprehensive guide to all of the last series can be found in the Doctor Who Series Two Companion, on sale Thursday 10 August, priced £5.99.