Marina Lewycka’s immensely appealing new novel continues the concern with immigrant life and unglamorous vehicles first displayed in her spirited fictional debut, A Short History of Tractors in Ukrainian (2005). The two caravans of its title are temporary home to an assortment of foreign workers (Polish, Ukrainian, Moldovan, Chinese, Malawian) strawberry-picking in Kent. For most of them, the garden of England initially seems not far from the Garden of Eden. Their job is exhausting, their accommodation is cramped, and they are monstrously underpaid. But it is almost midsummer. Dappled sunlight sparkles through hedges of hazel and hawthorn. Thrushes sing from copses. In the evening, scents of honeysuckle waft out.

One of the group, a dab hand at culinary improvisation, magics their dismal rations into memorable feasts with the help of gleanings from the local countryside: two pigeon eggs, a rabbit, wild mushrooms, green leaves of wood garlic, mauve thyme flowers to spice dumplings. Strawberries marinated in cool tea with sugar and mint leaves round off the repast.

Needless to say, this pastoral idyll doesn’t last — though the atmosphere of healthy resourcefulness it establishes persists even through scenes where the migrant workers’ rosy views of England take a battering. Misadventures soon scatter the book’s personnel down various corridors of exploited labour: stomach-turning sequences amid the reeking horrors of a Norfolk poultry farm, glimpses of the sex industry’s insatiable appetite for cheap new flesh, frazzled episodes in a London restaurant kitchen. Since Two Caravans is a comedy, nobody decent comes to grief for long. But you’re continually kept aware how easily they could have done so. Sombre actualities shadow the ebullient story — not just in the form of spirit-breaking, bone-wearying jobs, but also in flashbacks to the thwarted, opportunity-starved lives the immigrants are trying to pull themselves away from. The bleak back-story of even one of Lewycka’s most unlovely characters — a ruthless spiv from a war-torn former Soviet republic — makes it impossible not to feel some sympathy for him despite the havoc he has wrought. Humane generosity of response vivifies the novel everywhere.

Two Caravans takes lines from The Canterbury Tales as its epigraph. But its characters don’t so much call to mind Chaucer’s pilgrims as HG Wells’s jaunty, underprivileged heroes — Kipps or Mr Polly — pluckily battling against disadvantage, enduring awful jobs with crushing hours and poor pay, and relishing escape into the restorative freshness of the English countryside.

Not that there’s anything derivative or sepia-tinted about this book. Much of it is as up to date as an avian-flu-scare headline. Displaced persons — in particular, arrivals from former outposts of the British empire — have been central to a great deal of contemporary fiction. Lewycka focuses on recent instances of them, in all their mettlesome diversity. Dover’s Admiralty Pier, two of her characters discover, is now demarcated into zones for fishermen of different nationalities — Bulgarians, Baltics, Ukrainians and Bela-russians, Africans, Balkans (Serbs, Croats, Albanians) and, at the far end, “Angliski”. Exploring territory that would be a UKIP nightmare, the novel traces the fanning-out across England of new economic migrants. Fascinated by it all, Lewycka is keenly informative about the circumstances in which these immigrants are plunged.

A lively love story between two young Ukrainians — Andriy, a miner’s son, and Irina, the daughter of academics — entertainingly zigzags in and out of misfortunes, misunderstandings and miscalculations that keep deferring their getting together. Class barriers, their situation reminds you, can be as divisive as national ones.

Around them, the novel brims with comedy — much of it, in keeping with the polyglot cast, of a linguistic kind. When an old people’s home (housing the elderly Romeo who was the hero of Lewycka’s previous novel) bursts into flame, someone fears it’s the work of “firomaniacs”. A repellent Russian people-trafficker attempts to allure Irina by flicking his greasy ponytail at her, while hoarsely confiding, “I heff hear that voman is cannot resisting such a hair it reminding her of men’s oggan.” Andriy, who visited South Yorkshire as a small child in the 1980s with a Ukrainian miners’ fraternal delegation, treasures memories of “the visionary blind man of Sheffield”, Vloonki, “known throughout the world for his progressive policies”, until talk of “bloody Blunkett”, who sold out “for a mess of posh totty”, dispels his enchantment.

Lewycka’s eagerness to enter into a wide range of consciousnesses leads her into one tactical error. Paragraphs in block capitals that intermittently break into the narrative and unleash the reactions of a labrador collie who plays a trusty role in the action (“I AM DOG I RUN” etc) are unlikely to be relished by anyone but the most ardent Crufts devotee. Everywhere else, this novel, which all but sings with zest for life, could hardly be more engaging, shrewd and winningly perceptive about the waste inflicted by prejudice and injustice.

TWO CARAVANS by Marina Lewycka

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