Anyone who has read the novella by Franz Kafka, Metamorphosis, will recognise the line. "One morning Gregor Samsa awoke from troubled dreams to find he was transformed into a monstrous insect/vermin/cockroach" (depending on the translator) - it's one of the iconic first lines. Kafka called it his 'bug book'.

McEwan's retelling is superficially a 'reversal' of Kafka. While Gregor Samsa, a travelling salesman, awakes to find himself changed into a cockroach, Jim Sams, a cockroach, awakes to find himself Prime Minister of the UK.

He is facing the task of a Brexit-like surrealist event, 'Reversalism', mandated by an ill-advised plebiscite.

Metamorphosis endures as one of the most perfectly ghastly imaginings of a human moral predicament; Kafka himself described the piece as he was composing it as 'extremely repulsive' and 'nauseating', and professing himself 'not unhappy with it'.

McEwan replaces Kafka's horror with farce. And the angst is transposed onto the context beyond the book, while the text maintains a determined cheerfulness throughout.

The 'reversalism' that is the political catch cry, has been embraced by the cockroaches of Westminster, but they scuttle away leaving others to deal with the consequences.

Ian McEwan is not Kafka, although he has an impressive literary pedigree and has won the Booker Prize, which is a kind of literary anointing.

His own style is often close enough - the early work has been described as 'twisted and dark', later showing the capacity for black comedy and cruel satire.

This is a book that bristles with in-jokes. It is not actually a retelling of Metamorphosis, and it is replete with other ironies. For example, the freehand quotation of Kafka's opening paragraph meets the charge of years before, that McEwan had 'plagiarised' another novelist's work.

The loose branding of the Brexit moment as a bad dream riffs on the surreal qualities of Kafka's book without ever leaving the safe shore of satire. Jim Sams is 'clever but not profound', which may be McEwan's tribute to the greater literary calibre of Kafka's character Gregor Samsa.

After the opening paragraphs, the similarity to Metamorphosis ends. There is no dark anguish in The Cockroach, as Jim Sams and his pheromonal friends 'get it done' with brio, and then slip through the cracks.