Following an onstage costume malfunction, and with only a few days to spare, Bridget Christie found herself completely rewriting her Edinburgh Festival Fringe show.

“It was all by accident really,” she admits while out in London with her children only days after her return from Edinburgh.

“The show in June wasn’t the show I performed in July, and even by August it had changed by about 50%.”

Having tackled politics in her last Fringe show, she found herself slowly focusing on religion, from the point of view of someone with faith.

“I did two Catholic jokes in early previews and had people coming up to me afterwards to say they liked hearing somebody talking about religion without taking an atheist point of view,” she says.

Since that epiphany the show changed to include a recreation of Christ’s accension to heaven using a giant fishing pole, and an opening section featuring Christie in the garb of a Catholic bishop with hairy hands.

It’s not quite what you’d expect from the wife of Stewart Lee, who was hounded by the Christian Right after co-writing the libretto to the West End hit Jerry Springer The Opera.

“There are comics who are religious but never talk about it on stage as they don’t want to come across as mental,” she laughs.

“You don’t want to be flippant either and make jokes about something that is quite close to you. I think you have to go for it sometimes and just suffer the consequences.

“It was quite surprising though, no one at the previews in London was negative or hostile or anything like that. I want to split people so they either hate it or love it – that’s my goal. If people just applaud politely you’ve not achieved anything.

“I think I’ve got to the point in my life where you think about things, and if you haven’t got a point or anything to say it probably isn’t worth doing.”

On her previous tour, A Ant, which focused mainly on politics, Christie took on the persona of the titular insect comic for a pointed series of observations on sexism and assumptions about female comics.

It was a method she was hoping to repeat in this year’s show, using a new character called Japanese Knotweed as a metaphor to comment on immigration and racism. That was until one fateful July night during a London preview.

“I did a preview opening as myself and then moving to Japanese Knotweed,” says Christie.

“It took me ten minutes to cut myself out of the costume – I had to ask for a knife from the kitchen.

“With character shows you can lose the flow if you’re having to get in and out of the costume. I had to carry on doing my material while cutting myself out.

“It was funny, but I couldn’t recreate that every night – by the end of the Fringe there wouldn’t be a costume left!”

Rewriting the show saw Christie take a whole new approach to writing.

“I thought about what I wanted to say, and wrote it in short paragraphs,” she says.

“Then at the end of each paragraph I would put in a joke, so I wasn’t rambling on for ages.

“I have never written like that before. You can’t talk about something like religion, which is quite a heavy subject, without lots of jokes.

“It has taken eight years to realise that I need to put jokes in!”

* 7.45pm, £12/£10, 01273 709709