BOB Gale sounds like a proud parent when he talks about bringing Back to the Future to the stage.

As the screenwriter behind one of the most successful and popular movie franchises of all time, you can understand his passion for the project which will see Back to the Future the Musical enjoy a world premiere in Manchester next year.

And he’s not alone in his excitement. For fans around the world, this is a moment they have been waiting more than 30 years for.

Which prompts me to ask, what has taken you so long?

Bob laughs at the question but gives a passionate explanation.

“Actually we’ve been thinking about this since 2004,” he said. “It’s taken so long because it’s not just doing the show, it’s doing the show right. We went up a lot of different blind alleys.

“We had meetings with producers who just didn’t get it or they’d say they did but then Robert Zemeckis (the film’s director and co-writer of the stage show) would just look at each other know they really didn’t understand what were were trying to do. It was like hiring the right tutor for your kids.

“We went down a number of dead ends and part of that was because Bob and I were new to this world of theatre and initially we didn’t know what we didn’t know, if that makes sense.”

With Bob and Robert in charge of the script, they turned to composer Alan Silvestri and Grammy-Award winning songwriter Glen Ballard to produce the music for the show. But even then, this heavyweight quarter found it impossible to get the show off the ground in America.

“Broadway can be a little exclusive club,” said Bob. “You see the same names going around from show to show. We were very much the new kids on the block trying to get in from the outside.”

Eventually they looked across the Atlantic and Bob reveals; “Creative people in the UK seem a lot more open to outsiders coming in. Nobody ever rolled their eyes at the idea that we wanted to do this.”

After an initial false star in 2014 - “we parted on good terms but the there were creative differences with the director” said Bob - everything is now set to bring the show to the stage, opening in February at Manchester Opera House.

“It’s very appropriate that Back to the Future should find its home in the UK,” said Bob. “There is a massive fanbase here.”

The stage shows long gestation period mirrors the struggles Bob had in getting the movie filmed in the first place.

“After the second draft of the script, Columbia passed on it as they said it was too nice and too sweet,” said Bob. “They were more into making teen comedies like Porkies at the time. Then when we took it to other studios the standard response was “time travel movies don’t make money”.

“That was true at the time. They just didn’t have the right time travel movie!”

When it was finally released, Back to the Future became the biggest grossing movie of 1985 and spawned two equally successful sequels.

Now Bob is working hard to ensure that the next chapter meets fans’ exacting expectations.

“Whether it’s at a comic convention or a De Lorean car show I’m always touched by the love that people have for the franchise,” said Bob. “It’s like having your child give you a hug - you can never have too many of those can you?

“But that is why Bob and I are so determined that the stage version has to be right. So many people are invested emotionally into the story of Marty and Doc, we won’t let them down.”

At workshops for the stage musical fans have been invited to attend in small groups to give their feedback and Bob says that their response has been tremendously positive.

And he has a reassuring words for those fans - “there will be a De Lorean, there will be lightning and there will be Calvin Klein underpants,” he laughed. “There are certain things which we are having to change because we are on stage but no stage adaptation of a movie should be a slavish copy.

“We now have other tools in the toolbox we can use including song. It’s been important to learn what we can do with a song, just as you have a close-up in a movie in a musical the equivalent is a song.”

Some of the movies iconic music including The Power of Love and Johnny B Good will feature prominently in the stage show.

“They are integral to the story,” said Bob. “If they weren’t there you’d feel you were being ripped off wouldn’t you?”

As the man who wrote the story, what does Bob put its universal appeal down to.

“At its heart it is about family,” he said. “Everybody is interested in where they come from and what their parents were like.

“The message of the movie is that you have control over your destiny - the choices and decisions you make will affect things later on.”

Bob is constantly flying over from the States as rehearsals for the show step up.

“I’ve constantly got a big smile on my face,” he said. “This is just going to be so good.”

Back to the Future the Musical, Manchester Opera House, February 20 to May 17. Details from www.atgtickets.com or 0844 871 3018