Partly because any new work by Jim Cartwright is eagerly anticipated, but the interest in The Gap which has its world premiere in Manchester is also down to the casting.

Matthew Kelly and Denise Welch play Walter and Corral, friends in their youth who haven’t seen each other for 50 years. He’s remained in the North, she’s ‘down South’ and then a chance phone call reunites them.

Bury Times: Matthew Kelly and Denise Welch

“There are joys and pitfalls which come from doing a new play,” said Denise. “You’ve got no reference points of what worked or what didn’t work in a previous production but you also have the joy of being the first people to ever play the characters and bringing any nuances or characterisations to them. You’re there, having it grow in front of you.”

An added bonus has been having Jim Cartwright, the man behind classics including Road, Two and The Rise and Fall of Little Voice in the rehearsal room.

“I said on an interview we did with Good Morning Britain that I have been in two of Jim’s plays before and the experience is like childbirth,” said former Coronation Street star and Loose Women presenter Denise. “You are so in love with the result you forget about what you go through to get there.

“And it’s true. Although Jim writes in a very naturalistic way - and this is a kind of a paradox - he also is so very stylised and very poetic. There is a rhythm and a pentameter to it all which you have to be mindful of.

“There is a lot of words and he writes in a non linear fashion. For a lot of play the characters are both out front but what you are saying is not a cue to the other person.

“There are completely different stories going on simultaneously. It’s challenging but I probably wouldn’t have it any other way to be honest.”

One thing Denise clearly wouldn’t have any other way is the choice of her co-star.

Bury Times: Matthew Kelly and Denise Welch play friends reunited in The Gap

“I can’t imagine doing it with anyone but Mrs Kelly off the telly,” she laughed.

The pair first met almost 25 years ago when Denise appeared on a celebrity version of Stars in Their Eyes, hosted by Matthew. She transformed herself into Petula Clark to sing Downtown.

“We’d kept in touch ever since,” she said, “and when I knew that Matthew had done a workshop version of The Gap I knew I wanted to be in it with him.

“It’s challenging as there are only the two of us on stage for the whole time. No one else is coming on to help us.

“It would be an absolute nightmare, and I’m sure there are many plays where it’s happened, where two actor don’t get on as well as Matthew and I do. That would be a very unpleasant time. We do get on so well; we trust each other and we are fans of each other’s work which is so important. We can share in each other’s joy and in our terror and fear.”

Denise admits that the first read-through for The Gap was the most nerve wracking.

“I just thought ‘how am I going to learn this play?’” she said. “After all neither of us are spring chickens any more. But as well as being nervous, we were both so excited about the prospect.

“That’s the thing with Jim’s writing - he totally gets people. Even now there is the odd line which just blindsides you, it is so beautiful.

“Then again there have been times when I’ve just stopped and gone ‘Jim what do you mean with this line? There’s only you that speaks like this.’

“It winds him up and he jokes ‘you wouldn’t do that with Shakespeare would you?’. The thing is, I probably would.”

Given that her career has seen her become a familiar face on TV - she’s been in Benidorm and Hollyoaks as well as reality shows such as Dancing on Ice and Celebrity Big Brother - which she won in 2012 - some might be surprised to see Denise in the intimate setting of Hope Mill Theatre.

“I’ve been very lucky that my career has allowed me to diversify into presenting and be a little bit of a personality and do all those different things, things which helped me stay relevant,” she said. “But at my core I’m a theatre trained stage actor as is Matthew and that’s what we do.

“I’d sort of forgotten that until I started work on this production but I felt the need to do it with a writer that we love and a director that we know and in a theatre I’m a patron of and which is one of my favourite theatres.”

Rehearsals complete, Denise and Matthew can’t wait to get The Gap in front of an audience.

“When I made decision to do this, a new play, I wanted to do it in this kind of venue. It’s terrifying but actually that’s part of the appeal. I’ve no desire to be in a big theatre. I wanted that intimacy.

“All of Jim’s plays work wherever they are performed because they are brilliant but this is the environment that is just right for this play.

“We have no idea how audiences will react. In rehearsal you work in front of the same people in the room day after day but they are not an audience; they are working too, making notes, considering technical things.

“People have already asked if the show has a future after the run. Blimey we don’t know if it will have a future after the second day,” she laughed..

“Of course it would be lovely but both Matthew and I have said let’s just get it done here and should anything happen we will discuss it.”

So what does Denise hope that audiences will take away from the show?

“There is a feeling of nostalgia for possibly older theatregoers as we do back to the Sixties for the start of their relationship,” she said.

“We know that Walter and Corral have never been romantically involved but it is still a love story. I’ve seen it described as a comedy but it’s more than that. It’s very funny in parts but it’s also moving, it’s got many layers to it.

“I’d like people to go away with a lovely warm feeling and perhaps think ‘you know what? They weren’t bad those two were they?”

The Gap, Hope Mill Theatre, Manchester, until Saturday, March 9. Details from