Much-loved British children's authors including Diana Wynne Jones and Jacqueline Wilson are pitted against the cream of international children's fiction in the Astrid Lindgren memorial award, the richest children's book prize in the world.

Britain has mustered a strong contingent for this year's prize - worth SEK5m (around £440,000) - with illustrator Quentin Blake, writer and illustrator Shirley Hughes and authors Michael Morpurgo and David Almond also in the running. Carnegie prize and Hans Christian Andersen award winner Aidan Chambers also makes the line-up, nominated twice, for his writing and for the work he does with his wife Nancy Chambers to promote reading.

"I don't think I have a hope," said Chambers, "up against that competition even from my own country. And the field is pretty strong when you look at the international line-up too." There are 168 candidates for the prize this year, with Australia's Morris Gleitzman and Shaun Tan, New Zealand's Margaret Mahy, Germany's Axel Scheffler - illustrator of the Gruffalo books - and Ireland's Kate Thompson all nominated by literary organisations in their countries.

The award was established in 2002 by the Swedish government following the death of Pippi Longstocking author Lindgren, aged 94, and is given to a body of work "in the spirit of Astrid Lindgren, with a focus on a profound respect for democratic values and human rights". Previous winners include Philip Pullman, Maurice Sendak and Sonya Hartnett.

"It's nice to be on the list but I'm not going to hold my breath," said Chambers. "I've been on it every year since it started [so] my form is not too good. If I were a racehorse, I wouldn't be backing me."

The winner of the prize, selected by a 12-member jury of experts in children's literature and children's rights, including a member of Lindgren's family, will be announced on 24 March at Lindgren's birth place in Vimmerby, Sweden.