The man behind Mrs Brown speaks to The Project

The man behind the world's most famous elderly Irish woman has opened up about playing Mrs Brown.

The eponymous matriarch of sitcom Mrs Brown's Boys has become an icon thanks to Brendan O'Carroll's performance - but he was never originally meant to play the character.

"I had an actress booked but she got a kidney infection," he told The Project. 

When the editor saw the footage - and heard the now-iconic Irish accent - he said O'Carroll had to keep playing the character.

He says acting for a regular television show is very different to being a theatre performer.

"Of your six performances in a week, you'll have two great performances, two okay performances and two dreadful performances. But if you've done your work, the audience won't know which is which.

"But now I've got to nail it every time."

He says he doesn't get recognised much - in fact, he's taken many photos of his wife, who also stars on the show, posing with fans in public who didn't realise they were standing next to Mrs Brown herself. 

His new live show, For the Love of Mrs Brown, is touring New Zealand and will perform at Spark Arena in Auckland this week. 

It revolves around the foul-mouthed Irish matriarch finding love after her daughter introduces her to the internet. 

"She knows her legs have been together longer than the Rolling Stones," says O'Carroll.

In the first episode of All Round to Mrs Brown's, the talk show spin-off of the original show, O'Carroll shared a passionate if surprising kiss with singer James Blunt. 

"My wife said 'you must have got such a shock'," he says of the on-screen smooch. 

"But actually he's a really nice kisser. I think he had a bottle of beer in his pocket as well, I wasn't sure."

Watch the full interview on The Project. 

Newshub.