A ctors John Challis and Sue Holderness have been friends for many years. In fact, as Sue tells Go!, the couple have had the longest comedy marriage on TV – even longer than Terry and June.

In their on-screen incarnations as Boycie and Marlene, the pair have worked together for more than 25 years in Britain's best-loved comedy series Only Fools And Horses and their own more recent spin-off series The Green Green Grass. Unknown to many, they have trodden the boards together in a series of Alan Ayckbourn plays and have done the occasional An Audience With... show on board cruise ships.

It's a bigger and better version of this stage show the pair will be bringing to the Assembly Hall in Tunbridge Wells this month.

Still loving her role as the brassy Marlene, with a soft spot for fake fur, big hair and Del Boy, Sue started with Only Fools And Horses in 1984. So what is it about Boycie and Marlene that still has people interested?

"People just seem to have a lot of affection for everything to do with Only Fools And Horses," says Sue. "And I think lots of people know a Boycie and Marlene, they say 'there's a couple at my local pub who are just like them'. I wonder just how many Boycie and Marlenes there are!"

Having started out as one day's work as the wife of Boycie, Sue was later asked back and the rest is history. With the end of Only Fools And Horses after the 2003 Christmas special, she assumed her days as Marlene were over until John Sullivan suggested a spin-off, The Green Green Grass. The series was a huge risk, particularly taking Boycie and Marlene out of London and placing their antics at a secluded farm in Shropshire. But it was a surprise hit and four series followed.

Unsurprisingly, after so many years, Sue and John get on really well and that's a good thing when you're touring the country with a live show.

"We have a shorthand when we work together now, because we know each other so well. You don't have to say 'I wonder if you'd mind awfully if you hurried up' – you can just say 'Oh, for Christ's sake, just hurry up!' And we understand each other's timing. It's very comfortable – it's like putting on an old pair of slippers."

So just what does an evening at the theatre in the company of Boycie and Marlene consist of?

"We're not in character all the time," says Sue. "We're a bit of both. We discovered that actually audiences quite wanted to see us as Boycie and Marlene so we come on as them and we do about four or five new little scenes – vaguely related to the place we're in and the situation we're in.

"But then we speak as ourselves and we talk about how we got offered the roles and then of course there's a wonderful opportunity for us to show some of our favourite clips. And we tell the story of how The Green Green Grass came about and at the end we have this half-hour set where the audience ask us any questions that intrigue them."

With the British public having such strong feelings for Only Fools And Horses, Sue says the show has being going down a storm on the first few nights of its tour.

"It's so rewarding. Very many people say to me that all through their lives – and it went on for such a long time that a lot of people weren't even born when it started – if they've come home a bit blue, they sit down in front of an episode of Only Fools And Horses and they know they can sit there with every member of the family and just have a family-bonding laugh."

By Caroline Read

Boycie And Marlene Assembly Hall, Tunbridge Wells Saturday February 13 at 7.30pm Tickets £18 from 01892 530613/532072 or www.assemblyhalltheatre.co.uk