She says it is a love letter to her parents, Melvyn Bragg and Marie-Elisabeth Roche.

It’s an expression of love for them, a way of confronting her continued grief over her mother and of detailing her love of her faith.

The fact that her dad has just turned 80 was also a prompt for Marie-Elsa Bragg to write her latest book.

Raw, honest and heartfelt, it’s a memoir made up of prose, poetry, religious reflections and letters to her mum and dad.

She calls Sleeping Letters a confession because she is facing up to the pain she has always felt since she was six when her mother committed suicide.

The Rev Marie-Elsa Bragg, duty chaplain of Westminster Abbey, meant to write a different book. A follow up to her debut novel Towards Mellbreak - that was a love letter to her beloved Cumbrian countryside and the folk who live off it.

She went on silent retreat to work on it, but the thoughts, emotions and feelings that came to her about her parents, life and her belief produced a very different book.

When she explains it, there are long pauses. As if gathering herself for what she is about to say, or guarding herself against the words to come.

It’s a serious subject that we deal with at a stately pace, but there are plenty of moments when her laughter bubbles over when talking about Cumbria, her writer and broadcaster dad and his recent wedding.

Open and eloquent, the book has only just been published, but already many people have been so moved by it, that they have contacted her.

Asked what the book is about, she says, finally: “A very long love letter to myself, my parents and to God.

“I was contracted to write a different book. I went on a silent retreat and this is what came out.

“It felt quite clear that I needed to do it.

“It was the right time. Dad is 80 and I was ready to say everything I wanted to say.

“Everything I could find, every ounce of love and soul I wanted to give, but I also wanted to face the pain and ask the question ‘ how do you really get through this?’

“How do you face the harsh realities of life, love and disasters and what comes out of it.”

She did not write the book thinking it would ever be published.

A collection of memoirs, letters and poems, she only handed it over to her publishers because they asked to see what she had been writing.

Her editors were so moved by it they pressed to publish it.

“I thought about it for a while and whether you could split out the poetry and prose and make more standard.

“I wanted to give my parents the creative bit of it. They wanted it raw, as it is.

“I could not really rewrite anything. You are in that state, or you are not. You can’t fake it.

“I handed it over and it is moving to see how it has been so helpful to so many people.

“There is the Christian Eucharist element to it, but hopefully it is universal, going through grief with a ritual to support you.

Now 54. She has had decades to live with her grief, her memories and her emotions. Why now?

“I have circled it all my life. This is a moment for me to really gather as a woman, everything i have found so far, and have my own creative conversation about it.

“It is my mother’s voice, my father’s voice and my voice.

“I found a real sense of peace afterwards. I felt I had come through something.

“I feel as though I have sent her off. I feel more at peace.

“As you grow and get older, you work a bit more out and feel you have a bit more to say.”

Her memories of her mother are vivid: “I only had her for the first six years. I savour those memories and my father has held ger very close all his life so she has always been part of our lives.”

She giggles when told she looks strikingly like her mother, a French artist and writer.

You wonder whether that has helped him or been too much of a painful reminder.

“Some of my dad’s friends friends say I’m actually looking more and more like his mum,” she laughs.

“We have always talked about her. He has this grief he has been unable to overcome.”

About 10 years ago, they both came up to their Cumbrian cottage as Melvyn wanted to write about Marie-Elisabeth.

“But he couldn’t face it fully - it just made it worse for him,” explains his daughter.

He turned to writing fiction, which Marie-Elsa says “did not help”.

He read Sleeping Letters in the summer and she adds: “He says he is beginning to find my book healing now and keeps re-reading it, but these things take time.

“This is my bid, before he goes, to find something that will help all three of us and maybe help each other.

“We are all getting older, wouldn’t it be wonderful if he could have a bit of peace in the next stage of his life.”

The “next stage” includes his new wife Gabriel Clare-Hunt whom he married at St Bega’s church on the shores of Bassenthwaite in September.

The decision to hold the wedding there is particularly meaningful for her: “There is a chapter in the book where me, my mother and father reconcile . There is a really loving moment we have together and I feel like there is something very healing about the synchronicity of it.”

Marie-Elsa took the service - and had to tell her dad off for crying.

“Not many people can say they have married their father- and I had to give the wedding speech,” she laughs.

“We had a rehearsal and spent some time by the lake and it was very moving and very humble. It was beautiful.

“After the rehearsal I had to be quite strong and say ‘you are not allowed to weep all the way down the aisle!’

“He was so moved when he came down the aisle and I was standing by the altar.

“He is not a man who weeps, but he was all teary-eyed.

“It was a really moving day and a lot of people felt that. At 80 how wonderful is it to be able to have another chance?”

Only just published, Sleeping Letters has already had a positive effect in helping people deal with bereavement. Marie-Elsa says she has had dozens of letters of thanks, adding: “It is very moving, in a good way.

“There are so many people out there who are dealing with grief and don’t know how to talk about it.”

The priest-turned author is thrilled to see Towards Mellbreak in paperback - and just as moved by the fact that a group of farmers have planted a tree in memory of the book’s main character, Harold.

Who knows what her next book will be.

n Sleeping Letters, published by Chatto and Windus), is out now, priced £12.99