Margaret Thatcher was in my year, and our first-year college photograph shows us standing side by side in the back row. We were both grammar school girls on state scholarships.

I like writing for children. It seems to me that most people underestimate their understanding and the strength of their feelings and in my books for them I try to put this right.

I like stirring the pot - I think it's part of my duty, to shake people up a bit - make them look at things in a different way.

Life isn't so complicated for children. They have more time to think about the really important things. That's why I occasionally moralise in my children's books in a way I wouldn't dare when writing for adults.

One good reason for writing novels based on your life is that you have something to read in old age when you've forgotten what happened.

All writers are liars. They twist events to suit themselves. They make use of their own tragedies to make a better story... They are terrible people.

But I don't write about sex for today's teenagers. Or Doc Martens boots either. I'm more interested in exploring how exactly the world is run, which doesn't really change that much from one generation to another.