"My journey to London is long and hard,” says Dick Whittington sadly. “Well, why don’t you take the X90, idiot?” jeers Dame Doris Donut, punching Dick fairly playfully on the arm.

It’s early days as I drop in on the Playhouse’s Dick Whittington rehearsals, and director Peter Duncan is still building up the degree of aggro between the characters. But there’s already no doubt so far as Reuben Kaye is concerned, because he’s playing arch-baddie King Rat.

“I know there’s a lot of aggro between me and every character,” Reuben tells me gleefully. “It’s on the cards at the moment that King Rat has a nice big sword fight with Dick. I’ve been fencing for years, and Ashley [Emerson, playing Dick] has done stage combat. It’s good to get a bit of swashbuckling in for the kids.”

In the absolute opposite corner in the goodie-versus-baddie stakes is Fairy Bow Bells, played by Deborah Crowe. “I have a strange relationship with King Rat,” Deborah says. “He’s almost like my naughty son. I don’t yet know whether Fairy Bow Bells is going to be motherly or Mary Poppins-esque.”

But don’t audiences expect panto fairy godmothers to be – well, a bit drippy? Deborah laughs uproariously.

“We may be slightly typecast as people who just come on and act as narrator. But I like to make my fairies gutsy.”

“I haven’t told you this,” adds Reuben, “But when I look at your fairy, it’s very Patricia Routledge. She is matronly, but still has a steely reserve.”

“But of course good is always going to overpower evil,” Deborah adds. “The audience knows everything is going to be fine, and King Rat will get his comeuppance. But the way our relationship is working at the moment is: ‘You’re a naughty schoolboy, stop messing. You’re annoying me now.”

But how does Deborah take to being compared with Patricia Routledge, alias the formidable snob Hyacinth Bucket in TV’s Keeping Up Appearances?

“This is the first I’ve heard of it. But I am a huge fan [and here Deborah switches on a good Hyacinth impersonation]: ‘Watch that pedestrian on the pavement, dear’. And yes, when I started talking with Peter about the Fairy, he did envisage a mumsy type – not that you will be able to tell from my extravagant costume!”

Panto is a uniquely British institution, found nowhere else in the world – not even in countries that were once part of the Empire. Reuben is Australian, so how did he first hear of the phenomenon?

“I used to be in Neighbours, and some mates on the show had come over and done panto. They said: ‘It’s amazing, you have to do it. It’s hard work, but it’s the most fun you will have on stage with an audience’. And since I moved here, my mother has insisted on me doing a panto: I’ve been in showbusiness for about ten years doing big shows, but only now does my mother believe I’m a legitimate performer.”

Deborah also didn’t discover panto via the traditional route of being taken along as a small child.

“I grew up in the Middle East, so there was no panto. I remember being an angel in a school production, wielding a wire coat hanger with a bit of tinsel hung round the top. But that was pretty much it – the temperature was usually about 35 degrees on Christmas Day.

“But when I was first in a panto three years ago, here at the Playhouse, it came quite naturally, because I love the whole business of interacting with the audience: every performance is different because every audience is different.”

Every audience is indeed different, but Reuben is plainly already well aware what reception King Rat should be getting.

“I’m working hard to get the maximum number of boos and catcalls,” he says. “It will be so much fun.”

Until January 13

Box office: 01865 305305. www.oxfordplayhouse.com