When Roddy the pet mouse (voiced by Hugh Jackman) is unceremoniously flushed down the toilet, his luxury London life is replaced by a non-stop round of chases, confrontations and narrow squeaks in the sewers below.

Down there, it’s a whole new world – the criminal Mr Big is a toad (Ian McKellen), nice rat Rita (Kate Winslet) has her own boat and then there’s Jean Reno’s Le Frog. Beautifully made by DreamWorks and Aardman, the studios behind Shrek and the Wallace and Gromit films, this is a superb computer-animated comedy adventure, with loads of pacy action and great gags.

Many of the best jokes are in the rich background details (such as the singing snails),  the slapstick action is non-stop and the dialogue (Dick Clement and Ian La Frenais had a hand in the script) is full of great lines. And that bit of back story involving Prince Charles is priceless.