LAURA Main bursts out laughing when I ask her how she’s getting on with her girdle

“Oh don’t,” she says. “my, that was a scene wasn’t it?”

In the Christmas special for Call the Midwife, TV viewers saw Laura, who plays doctor’s wife Shelagh Turner, struggling with her foundation garments as she was once again coming the rescue of her beleaguered husband, played by Stephen McGann.

“It certainly provoked a lot of laughter in my family on Christmas Day,” she said. “I watched it through my fingers.”

For viewers used to seeing Laura as the highly organised and slightly prim doctor’s wife in the series set in 1960s’ East End, her latest role may well take them by surprise.

For she is starring as Princess Fiona in the hit musical Shrek which begins a major UK tour in Manchester this week.

The show spent five weeks in Edinburgh over Christmas allowing Aberdeen-born Laura the chance to catch up with family and friends.

“It’s odd really,” she said. “At the moment I don’t quite feel like I’m on tour as we haven’t taken the show out on the road yet. Once we get to Manchester, that’s when I think we will all realise it.”

Based on the Dreamworks animation, Shrek is the tale of a loveable green ogre who discovers that the love of his life is a real-life princess.

“It is a huge production to be part of,” said Laura. “I think I fully realised that when I was stood in the wings waiting to go on and four of the ensemble were on stage operating a 35 foot dragon.”

Although Shrek is her first major musical role, Laura has always had a passion for them.

“I was one of the Von Trapp children in a touring production of The Sound of Music when I was in Aberdeen,” she said. “I’d was already doing a bit of amateur theatre then and I’d played Annie in an adult production. I think I’d also been a Munchkin in a professional show by then.

“But to play a von Trapp alongside Christopher Cazanove and Liz Robertson was a special experience. It was probably the moment when I thought ‘you can do this for a living’.”

Laura, now 36, trained at the prestigious Webber Douglas Academy in London

“My first job was Alice in Wonderland at the RSC which was a production with song rather than a musical,” she said. “I’ve always tried to keep my hand in over the years and done some fringe productions. Musicals have always been a passion of mine but I’ve never done anything on this scale.”

As Princess Fiona, Laura gets to sing and dance - “I actually tap dance which is something new for me,” she giggled. She also has to transform from the fair princess into a green ogre.

“It can get everywhere,” she said about her make-up. “You go home and find there’s still green in your hairline or it looks as though you haven’t washed your neck properly.

“I think it’s a toss up between me and Steff (Steffan Harris who plays Shrek) as to who leaves the theatre last every night, it takes us so long to wash it off.”

Achieving the transformation takes far less time, however.

“It’s a bit like a Formula One pit stop,” said Laura. “I stand there are there are seven people from wardrobe, sound and make-up working on me - we have less than 60 seconds.”

It’s certainly a far cry from Call the Midwife which has become one of the most popular shows on TV. And the great news for Laura is that she will be able to divide her time between both roles during 2018.

“Growing up my main things to watch were musicals and period drams, so I’m so chuffed to get to do both this year,” she said. “I’m over the moon.”

Laura will spend the first half of the year touring with Shrek and then break off to film the eighth series of Midwife before returning to Shrek later in the year.

“There is going to be a little bit of going back and forth certainly,” she said. “It will be tiring but I will not be complaining. I’m really lucky to do this.

“It was quite strange watching the Christmas Special of Call the Midwife having just done a performance as Princess Fiona and knowing that I would be going back and doing it again on Boxing Day. “

I suggest that Princess Fiona has a bit more about her than the slightly dull Turner family.

“Oh no, don’t say that,” said Laura.”I’m incredibly fond of the Turners. Stephen McGann puts it very well in that you often get drama through conflict in many programmes; you don’t get that with the Turners, They are a very supportive and loving family.”

Shrek the Musical, Palace Theatre, Manchester, Tuesday, January 16 to Sunday, January 28. Details from 0844 871 3019 or www.atgtickets.com