BERWICK Kaler is fretting. “I’m not a comedian,” he says. “And I’m not going to be the voice of pantomime – though I know quite a bit about pantomime, but it’s just something you have to see to understand it.”

Berwick is speaking ahead of Thursday’s opening of Aladdin And The Twankeys, his fifth Aladdin in the 35th year of his damehood at York Theatre Royal.

Why is the grand dame fretting? “They want me to go on Libby Purves’s Midweek show on Radio 4 with Jo Brand, who’s doing her first pantomime in Wimbledon, and Henry Winkler, The Fonz from Happy Days, who’s playing Captain Hook at Richmond Theatre,” he says.

“All I’m saying is I’ll go down there, and it’s in front of a live audience, but what am I going to do? That audience isn’t going to know me, and how can you describe pantomime on the radio when it’s a form of entertainment that’s so visual?

“If you try to explain to them what’s good about our ‘rubbish’, you just sound big-headed, but if it they know your face, like they do in York, then you’re half-way there.”

The irony is that Dame Berwick has become the voice, the authority, on the subject of pantomime, drawing media attention from the national press and media because of his longevity and creativity in York.

“Jo Brand and The Fonz just need to walk on to do Midweek and the audience will know her humour and they’ll know The Fonx, so it’s easier for them down there and easier for me in York, and the trouble is I got my little bit of fame staying in the same city for 35 shows in 37 years, and I have to come up with something new every year for that city.”

Hence the change of name to Aladdin And The Twankeys, freshening up a pantomime that Berwick’s dame Widow Twankey has washed her linen in public previously in The Lad Aladdin in 2005 and also in 1997, 1989 and 1981.

Dame and co-director Berwick prides himself as much as ever on writing an entirely new script.

“I just think you can’t be cynical about pantomime. The only thing you can criticise is if you bring in tired old sets, tired old jokes, tired old costumes,” he says. “What humour I have, I share with this Theatre Royal audience, who have grown up with me and Martin [Barrass] and Suzy [Cooper], and we still get laughs after all these years, so we must be doing something right.”

Seventy performances of Aladdin are expected to draw more than 50,000 panto punters between December 12 and February 1.

“You couldn’t plot or plan what’s happened here. Thirty seven years ago, when I first walked through the doors, I never thought I’d still be here talking to you and talking to Libby Purves, but it’s a unique show – and what is unique is the audience, the audience, the audience.”

At 68, Berwick is sort of semi-retired from his life as a jobbing actor, giving him more time to focus on the script and visual-gag ideas for his pantomimes.

“I always wanted to be the first actor in the world to retire at 65, but we don’t retire, we just grow old, so I’ve put a stop to the television work,” he says.

“When I came to live in York from London about 12 years ago, I would do adverts, but you do have to audition for everything, so one thing I decided was there’d be no more auditions or adverts, just a bit of telly initially, and the panto at the end of the year.

“Then three years ago, I decided, ‘I’m not going to do telly for this kind of money as a jobbing actor’, as what they now pay doesn’t even come up to the level of the old expenses, when once I could pay the mortgage from the expenses for Spender. So it’s semi-retirement now.”

Having said “no more television”, Berwick nevertheless “did some TV with Anita Dobson” in a BBC1 show called Moving On. “I did it because it was Anita Dobson, who I’d met before, and my old friend Noreen Kershaw was directing,” he says.

“So now I just work for people who know me, know my style, know what they’re getting, but pantomime is really enough for me.”

Berwick always take a holiday in warmer climes immediately after the pantomime run, and then works on the next show’s synopsis in April in the study he calls his office.

“We then have to make arrangements for the costumes and the sets, which are all designed and made in York, when there’s still time to change your mind on the odd thing, and I don’t come back to the script until the end of July, so it’s not as if I’m leaving and breathing it all the time,” he says.

He presents a production script for “production eyes only” and then starts writing regularly in the morning, “nothing too strenuous”. “There’s an editing process going on, even before you go into the rehearsal room, and you kind of know how long the show is going to be from previous years of writing.”

Berwick writes on his own. “I’m sitting there in my ‘office’, thinking about what someone’s going to laugh at, so it’s quite a responsibility, and you’re always under pressure to come up with something new. Even if you’re doing an old routine, give it a new twist,” he says.

“Just doing the same routine is laziness. I may be getting on a bit, but I couldn’t be lazy.”

• Aladdin And The Twankeys runs at York Theatre Royal from December 12 to February 1. Box office: 01904 623568 or at yorktheatreroyal.co.uk