Frank Cottrell Boyce wrote scripts for Coronation Street

The Liverpudlian beat a shortlist featuring Philip Pullman to win the award with his book Millions.

It tells the story of two brothers who discover some money and have to spend it before sterling becomes obsolete.

Former winners of the medal, which was first awarded in 1936, have included CS Lewis and Arthur Ransome.

'Pacy'

Mr Cottrell Boyce said he was "chuffed to bits" to have picked up the award.

Choosing a winner from this year's shortlist was "a seemingly impossible" task, said judges' chairwoman Sharon Sperling, but she added their decision was unanimous.

Millions was praised for its "pacy plot" and "excellent characterisation".

Chris Riddell's illustrations won the Kate Greenaway medal

Mr Cottrell Boyce is an established screenplay writer, with films 24 Hour Party People and Hilary and Jackie - which gained him a Bafta nomination - amongst his credits.

He also used to write for long-running television soap opera Coronation Street.

His long-standing ambition was to write a children's novel. He originally wrote Millions as a screenplay, which was made into a film by director Danny Boyle.

A further children's novel called Framed is set for publication in September.

Political cartoonist for The Observer newspaper, Chris Riddell, won the Kate Greenaway medal for his work on Jonathan Swift's Gulliver.