Image copyright Kate Christer Image caption Sally Gardner won the Carnegie Medal in 2013

Author Sally Gardner is in the running to win this year's prestigious CILIP Carnegie Medal for children's writing, an award she won two years ago.

Her book Tinder is a reworking of the Tinderbox fairytale and features illustrations by David Roberts.

After her win in 2013, the writer - who is dyslexic - criticised the policies of education secretary Michael Gove.

Past winner Patrick Ness could win his third Carnegie medal for More Than This.

Gardner's collaborator Roberts has also been shortlisted for the Kate Greenaway Medal for illustration in children's books.

Dark themes run through the shortlist for this year's Carnegie Medal with nominees including Buffalo Soldier, Tanya Landman's novel about an ex-slave now serving in the post-Civil War US army and Frances Hardinge's Cuckoo Song. Geraldine McCaughrean's The Middle of Nowhere begins with a child losing her mother to a snake bite in the Australian Outback.

Agnes Guyon, the chair of this year's judging panel said: "There's no doubt our writers and illustrators do not shy away from difficult, often painful imagery and themes. There is darkness here, illuminated by the bright light of optimism."

The full list of Carnegie medal nominees are:

When Mr Dog Bites by Brian Conaghan (Bloomsbury)

Apple and Rain by Sarah Crossan (Bloomsbury)

Tinder by Sally Gardner (author) and David Roberts (illustrator) (Orion Children's Books)

Cuckoo Song by Frances Hardinge (Macmillan Children's Books)

The Fastest Boy in the World by Elizabeth Laird (Macmillan Children's Books)

Buffalo Soldier by Tanya Landman (Walker Books)

The Middle of Nowhere by Geraldine McCaughrean (Usborne Books)

More Than This by Patrick Ness (Walker Books)

Image copyright Press handout Image caption Book for older children dominate the illustration prize

The Kate Greenway Medal sees competition coming mainly from books for older children rather than traditional picture books.

John Higgins and Marc Olivent's work in the graphic novel thriller, Dark Satanic Mills is up against William Grill's non-fiction work, Shackleton's Journey.

The full list of Kate Greenway Medal nominees are:

The Promise by Laura Carlin (illustrator) and Nicola Davies (author) (Walker Books)

Jim's Lion by Alexis Deacon (illustrator) and Russell Hoban (author) (Walker Books)

Shackleton's Journey by William Grill (Flying Eye Books)

Dark Satanic Mills by John Higgins and Marc Olivent (illustrators) and Julian Sedgwick and Marcus Sedgwick (authors) (Walker Books)

Smelly Louie by Catherine Rayner (Macmillan Children's Books)

Goth Girl and the Ghost of a Mouse by Chris Riddell (Macmillan Children's Books)

Tinder by David Roberts (illustrator) and Sally Gardner (author) (Orion Children's Books)

Rules of Summer by Shaun Tan (Hodder Children's Books)

The winners for both the Carnegie Medal and the Kate Greenaway Medal will be announced on 22 June with the winners receiving £500 worth of books to donate to their local library.

The Carnegie Medal was established in 1936 in memory of the Scottish-born philanthropist Andrew Carnegie with the Kate Greenaway Medal following 19 years later, named after the popular 19th-Century artist.