TO millions of TV viewers Gwyneth Strong will be forever remembered for playing Cassandra in one of the greatest sitcoms of all time, Only Fools and Horses.

Now she is touring the country in another national institution, Agatha Christie’s The Mousetrap, which comes to The Lowry, Salford Quays, later this month.

The thriller has become a legend in the theatre having played in London’s West End since 1952 - the is currently running at St Martin’s Theatre and more than 27,500 performances have been enjoyed by theatregoers.

Gwyneth will be part of only the second national tour of the murder mystery - the first marked the 60th anniversary of the show in 2012.

Given The Mousetrap’s legendary status, you could forgive Gwyneth and the rest of the cast for feeling the tradition weighing heavily on their shoulders.

“Actually,” she said, “I think because it is so well established takes the pressure off. A lot of theatre I have done are new works and that’s very risky because people might not just like it .

“But something like this has more than proven itself.

“It’s actually rather reassuring to be part of something that’s been tried and tested in this way. Plus with The Mousetrap, you’re going to be part of history – I really love that idea.”

Agatha Christie is one of the country’s best-loved thriller writers but although she’s now starring in one of her most famous works, Gwyneth has a confession to make.

“You know, I think I’m the only person who hasn’t read any of her books,” she said. “I’d seen all the film and the TV versions which I really love but for some reason I’ve not read any of the books.

“So when I got the script for The Mousetrap, that was the first Agatha Christie I’d ever I read - and I loved it.

“I was just so surprised at how quickly I got sucked in. I was supposed to ring somebody back when I was reading it and thought that when I got halfway through I’d make a cup of tea and ring them back but I never did. I couldn’t stop until I got to the end.”

Gwyneth plays the fearsome, complaining Mrs Boyle, one of the guests snowed in at the foreboding Monkswell Manor.

“One of the things that attracted me to wanting to do is that Agatha Christie is incredibly good at writing women,” she said. “All her female characters are different, difficult women. This character is quite bombastic and angry and as an actress I just thought ’I’d love to have a go at that’.

“When you think of when she was writing those women, I think she was very ahead of her time.”

The Mousetrap has managed to retain its mystique for over 60 years with the audience being sworn to secrecy and not reveal who the murderer is at the end of each performance - not something that Gwyneth’s likely to divulge.

“In my family I’m known for not being very good at plots,” she laughed. “When I watch a thriller with my husband (Eastenders and Eldorado star Jesse Birdsall) he gets so sick of me going ‘pause it’ so that I confirm what I’m thinking or he points me in the right direction and then we can carry on.

“I’ll probably get the hang of this one later than everyone else even though I’m in it!”

With the show being a permanent fixture in the West End, Gwyneth and her fellow cast members in the touring version were able to enjoy a unique rehearsal period.

“We were able to rehearse on the stage with the full set on the days that the show wasn’t running,” she said. “Normally you rehearse with a few bits of old furniture and tape marking out where everything will be. To be able to work with the set certainly made a change from having to mime having to open doors.”

The Mousetrap will be touring for most of the year with a series of dates already pencilled in for 2020 but Gwyneth isn’t put off by the thought of many weeks spent on the road.

“I don’t tour that often so when it comes around I’m ready to have a go at it and really enjoy it,” she said. “It’s a bit like escaping your life from time to time which actually I don’t mind.”

Gwyneth admits that she will always be seen as Cassandra, long-suffering girlfriend of Rodney Trotter, in Only Fools and Horses but she doesn’t resent it.

“Why would I?” she asked. “It was a fantastic experience for me. I love that show and I loved being in it. It’s only ever been something positive in my life - it’s opened a lot of doors for me.

“And the reaction I get from the public is always so positive, I don’t think you can complain about that. You just have to embrace it.”

n The Mousetrap, The Lowry, Salford Quays, Monday, May 13 to Saturday, May 18. Details from 0843 208 6005 or www.thelowry.com