Meg Rosoff has said she “literally never ever imagined” winning the Astrid Lindgren Memorial award, the most prestigious honour for young people’s literature in the world.

The Swedish award, which comes with a cash prize of £430,000, was awarded to the young adult fiction writer for a lifetime of acclaimed works such as How I Live Now and Just In Case.

Ms Rosoff admitted that she was “so glad to talk to the JC, because all I’ve heard from absolutely every person I’ve ever spoken to in my whole life is: ‘You must be drinking champagne, you must be dancing.’

“And I say: ‘Don’t you understand, I’m Jewish! I can’t! I’m here thinking: ‘Oh my G-d, something wonderful has happened; now someone is going to die.’

“I feel guilty, and that if something good has happened something bad will happen next. I think it's that darkness and pessimism which informs my writing, so I can’t regret it too much.”

And the 59-year-old author, who won the Carnegie Medal in 2007 for Just In Case, said that her Jewish background had come to the forefront as time went on.

“The older I get, the more culturally Jewish I feel, and the more I appreciate the Jewish intellectual tradition.

“I consider myself typically Jewish, in that I call myself a cheerful pessimist. Like in Fiddler On The Roof, you’ve got to dance while there are no pogroms.”

She said that the prize, named after the author of the Pippi Longstocking series, was “recognition from the Swedish government of the importance of books to children”, and chastised the British authorities for not following this lead.

“They go on and on about literacy in schools, but there are practically no schools in the country which can afford librarians. Literacy comes from books, and you have to give the right book to children to get them to read.”

The author also defended her genre of young adult fiction, which she said too many critics dismissed, asking her: “When are you going to write for real people?”

She said that in response, she asks: “‘When do you read the books that change your life?’ It's not when you’re 45. The books that changed my life were the ones I read when I was 11, 12 or 13.

“I talk to children about subjects I wish someone had talked to me about as a child: what does it mean to be different and not quite understand the edges of reality.

“I talk about things like war, love and gender, and the question which as a 59-year-old I’m still grappling with: how do you live a meaningful life?”

The writer, who moved to Britain in 1989 after growing up in the US, had “absolutely no idea” how she was going to spend the prize money, as she was “trying not to think about it. I’m definitely going to give some of it away though.”

In explaining why Ms Rosoff had triumphed over 215 nominees from 59 countries, the jury said her works “speak to the emotions as well as the intellect.

“In sparkling prose, she writes about the search for meaning and identity in a peculiar and bizarre world. Her brave and humorous stories are one-of-a-kind. She leaves no reader unmoved.”

Ms Rosoff will be presented with the award on May 30 at a ceremony in Stockholm.