When Hollywood director Gary Sinyor is on set with stars such as Renée Zellweger he wears two watches, one on the left arm and one on the right, as a reminder that time is money.

And when he first wrote the script for biblical comedy NotMoses he had to face movie executives asking him to secure a box office star such as Bradley Cooper for the lead role.

So the Finchley father-of-four decided to eschew the pressures of LA and instead bring his tale, of the crying baby who got thrown back in the Nile, to the London stage.

The 53-year-old’s voice is full of joy, with a tinge of surprise, as he tells me how much he is enjoying his first theatre production.

“I had a schedule for where I thought we would be and we are ahead of it.

“It’s nice to have days and days to rehearse with actors because on films you have two minutes and then you have to shoot.”

Set in Ancient Egypt, Gary’s play has tongue firmly in its cheek as it follows the exploits of NotMoses, who is rejected by the Princess in favour of the sweeter baby Moses and grows up a disgruntled slave. His story intertwines with the biblical tale of the Exodus, Ten Plagues and Ten Commandments, racing through 60 scenes, peppered with outrageous joke and visual gags.

“In a film you have 600,000 extras created by CGI but in theatre I can just make one guy hold a sign saying ‘I represent 600,000 people’ and you get a different laugh out of it,” explains Gary.

“It’s like when the Pythons would do a horse by banging coconut shells together. You have to improvise and come up with some more surreal and funnier and you have that immediate interaction with the audience which is more exciting.”

He first had the idea more than nine years ago, long before Book of Mormon took to the stage, and says his play draws on his Jewish upbringing, love of the underdog story and, more seriously, his views on religion.

“This is a bit blasphemous but I think that’s alright. The Life of Brian was banned but if you watch it now it really is quite tame. We are definitely more controversial but for our times its a similar kind of thing.

“Now you have Richard Dawkins and there’s is a whole atheism movement and we are exploring all of that. I think people who want to be offended will be but I think they will also be laughing.”

The show includes the characters making kebabs on the burning bush, pharoah being given gifts of cheese and black pudding and apparently answers the question: Does oral sex constitute adultery?

Gary, who is a member of New North London Synagogue in Finchley, says: “It does have a slight dig at the three Abrahamic faiths Judaism, Christianity and Islam all equally but not in an aggressive Charlie Hebdo way but more humorously. We are not trying to bring people down and put religion down but the message is that fundamentalism, wherever it comes through, in whatever religion, is a bit bonkers.”

He adds: “I think it’s unlikely that we can say god is this lovely, kindly person who listens when we ask ‘please can we all have a nice life’. I think it’s important that we all get on with life and living peaceably and find love and families and travel and do all the good things that life is about but not go around discriminating or punishing people who don’t agree with our beliefs.”

Raised in Manchester, Gary was set for a very different career, selling Head and Shoulders for Proctor and Gamble.

But when it fell through he had a ‘revelatory moment’ and realised film-making and storytelling was where his passion lay.

He moved to Muswell Hill 30-years-ago and after graduating from the National Film and Television School with BAFTA nominated The Unkindest Cut, he was commissioned by one of his heroes, Python star Eric Idle, to write Leon the Pig Farmer. It went on to win the Venice International Film Festival’s Critics Choice Award and the Evening Standard Award for Best Newcomer, his proudest career moment to date.

“The early stuff of Woody Allen and the Pythons have clearly had an influence on me so that was an extraordinary coincidence to meet him and some of the other Pythons as well," says Gary of the experience.

“I’m aware when I started to write NotMoses there would be comparisons to Life of Brian and I’m fine with that. People have said it as a negative thing but that is paying me the biggest complement in the world.”

When asked how directing it compares to working on a film such as The Batchelor Gary says: “Can I say that’s it’s easier, am I allowed?

“On a film set you go along and there’s 150 people and huge vans trucks and you get very little time to rehearse and play.

“Renée (Zellweger) was absolutely lovely but the amount of time I got with her and Chris (O'Donnell) was minutes not hours because the crew is standing by waiting to shoot.

“The pressure is so immense on a film director and every minute is precious. I would never have been able to have this interview on a film set because there would have been people over my shoulder.”

In contrast he says of NotMoses: “The joy of spending time with these nine people and eeking out every single potential moment of laughter or pathos or wonder is something I have never ever had on film.

“In theatre there is this sense of creating a company.”

Gary is hoping NotMoses will end up on Broadway eventually and has already had interest from America but he still loves films and is working on scripts for wedding comedy Something Blue and thriller The Unseen.

“Write,” he advises anyone wanting to emulate his career. “People obsess about directing and in particular film because you get power and tell people what to do and are elevated up to some huge status. But I think that is the wrong way to go about it.

“That ability to write the story you want to is the way in. You can put self-expression into writing whereas being a director you are working with what someone else has written. As a writer you are god.”

Arts Theatre, Great Newport Street, WC2H 7JB. March 10 to May 14. Details: 020 7836 8463, NotMosesOnStage.com