She says: ‘Harry had been left in a very hostile environment, so there are clear parallels. He is a boy removed from his family by bereavement.’ The author speaks candidly about how her ‘emotional anxiety’ about money is deeply rooted in her past.

JK Rowling has revealed the heartbreaking moment she almost snatched a baby from her cot in a ‘cold and frightening’ state-run so-called orphanage in Eastern Europe.

The Harry Potter author says her maternal instincts drove her to consider the unthinkable during a visit to the institution, which she claimed was more like a prison than a home.

She says: ‘I’m an emotional person. I struggle with that a lot in this kind of situation. There was one little baby, a girl, and I was standing at this cot and I just thought, “I will take her”.

‘It was irrational but that’s your human response. There was no earthly way I could take this baby home but that is your most powerful reaction. You think as a mother, “I will save this baby, this one baby”.’

She says: ‘The one incident that absolutely killed me was a little girl with physical disabilities who had been put into the institution and used to ask for her mother. The nurse would go outside and ring the girl and pretend to be her mother. Utterly heartbreaking.’

I still worry about money. Funnily enough it bears no relation to what is in your bank account, it is purely emotional,’ she says. ‘I was as poor as it’s possible to be in this country.

‘I was a single parent. The key phrase is “in this country” because we have a welfare state. I remember not eating so my daughter would eat .  .  . nights when there was literally no money, when I had one Rich Tea biscuit and that was dinner.’

She adds: ‘I was terrified of pressing the wrong button and losing everything, and having to look my daughter in the face and say, “We had a house and now through a stupid error .  .  . ” I don’t know what I thought I was going to do but my terror was making a ridiculous mistake and it all disappearing.’