Having languished in the British Intelligence vaults for eighty years, this TOP SECRET file is about to be revealed to wide-eyed young readers. Set during the darkest days of the London Blitz, it tells of one brave orphan’s battle against the might of the Nazi regime, with only an escaped gorilla and his tin-legged great-uncle Sid for company. Be prepared for espionage, a plot to bring Britain to its knees, and an awful lot of tickling, in Code Name Bananas by David Walliams.

In this WWII escapade, we join Eric and Uncle Sid, the oldest zoo keeper at London Zoo. United in their love of animals, the kindly pair fret over the impact of the nightly

Luftwaffe raids on the zoo’s inmates, and in particular, on a gentle gorilla named Gertrude. After a desperate failed bid to escape during a night of heavy bombing, a distressed Gertrude is brought in front of the Director General, who issues a terrible decree. As the potential consequences of a gorilla on the rampage in London are dire  ( just imagine she were to scale Nelson’s Column, gatecrash Claridges, or take a ride on the Tube!) Gertrude must be…gulp…put down.

For Eric and Sid, the only conceivable option is to snatch Gertrude and flee the capital in search of safety. Their agreed destination is Bognor Regis, on the Sussex coast. In theory a genteel English seaside town, in actuality a hotbed of Nazi plotting and intrigue. Here the action ramps up to the usual dizzy Walliams-eque heights, with a theatrical cast of characters that include Mr Winston Churchill himself.

I like the energy of Walliams’ writing and his gleefully outrageous imagination. For me, the only bum note occurs in a passage where a character is repeatedly mocked for having a speech impediment. Unpleasant and strikingly out of place in a 21st century children’s novel, it somewhat marred the read for me.

That aside, this is undoubtedly another stonking Christmas hit for Walliams.

Code Name Bananas by David Walliams is published by Harper Collins Children’s Books, 392 pages.