The executive producer of West End musical Wicked has admitted he did not think the show would last as long as it has, as the production celebrates its 10th anniversary.

Wicked tells the backstory of the Wizard of Oz’s witches Elphaba and Glinda before they became known as the Wicked Witch of the West and Glinda the Good Witch.

It has gone on to become an international success, and is the eighth longest-running show currently playing in the West End.

The cast of Wicked after the 1000th performance (Yui Mok/PA)

The original musical production made its debut on Broadway in New York in 2003, and a version was introduced at London’s Apollo Victoria Theatre in September 2006.

Michael McCabe, the executive producer of the UK production, said that he “never” took its success for granted and that it is “the last one standing” among other shows that opened around the same time.

He told the Press Association: “At the beginning, we opened in a very busy year for musicals and I don’t think anyone thought Wicked would be the one.

London’s Suzie Mathers as Glinda and Rachel Tucker as Elphaba (Matt Crocket)

“But we’re the last one standing of everything we opened up against, and that was an extraordinary thing to witness and realise we had this extraordinary traction with the public, and it rolls on.”

He added: “When we got to five years it felt extraordinary, so to have got to 10 years, even more so.”

McCabe added that he feels the show is “part of the London landscape” and hopes that it has “many, many years” left.

Idina Menzel as Elphaba on Broadway (Kathy Willens/AP)

He praised Tony Award-winning actress Idina Menzel, who played Elphaba in the Broadway version of Wicked and then in the West End when it opened in 2006, for “setting the bar high” for everybody who has taken on the role since.

McCabe said: “We’ve been very lucky, and Idina Menzel set the bar very high at the beginning, and therefore that’s always the bar we’ve had to aspire to. I think so many people have gone to that place, it’s always been very exciting to see.”

The 10th anniversary will be celebrated with a party and a special curtain call with various surprise guests.

During Wicked’s run, it has won two Olivier Audience Awards, an Evening Standard Theatre Award and nine WhatsOnStage Awards, and it has been seen by nearly eight million people in the capital alone.