Miriam guest stars as Sister Mildred.

With plenty of great quality viewing due to hit our TV’s during Christmas, Call The Midwife is set to wrack up the big viewing numbers during the big day.

Call the Midwife cast in Christmas Special 2018

Having secured a mega 9.6 million views last year, the hugely popular BBC drama is back once again for a festive special.

With a promised ‘upbeat’ episode, TV bosses have been thrilled at the arrival of actress Miriam Margolyes – who has joined the cast as Sister Mildred.

The TV legend will be playing the part of the nun, who arrives at Nonnatus House with four Chinese orphans who have fled the country.

Miram Margoyles guest stars in the Call the Midwife Christmas Special

Speaking of the role, Miriam, who is well-recognised for her defining role in Harry Potter, shared her disbelief.

“I thought I would be some sort of East End housewife or grandmother or something. It never occurred to me that I would be a nun. And not just any nun, an important one!”

Revealing her joy at being cast on the show, Miriam added: Call the Midwife shows the best of Britain and real communities. People use that word ‘community’ an awful lot these days but there doesn’t seem to be much community around – community spirit and friendship and kindness.

“And the show does depict people at their best, caring for other people and having fun together. I’m terribly proud to be in it.”

best Christmas shows 2018 including Call the Midwife Christmas special

However, despite her delight at finally landing a part on the BBC drama, Miriam insists she will not be tuning in with us tomorrow.

“I hope my performance was satisfactory – you always do – but I never watch my own stuff.”

Revealing what Miriam was like on set, actress Jennifer Kirby (who plays Nurse Valerie Dyer) said: “Something I really admire about Miriam is that no matter who she’s around, she’s always utterly and completely herself.

“She never minces her words or changes herself in any way, which is really amazing.

“She brought in this kind of new energy which was exciting and hilarious, there were certain scenes that we really had trouble getting finished.”