A Very Brassic Christmas review – Imelda Staunton’s guest appearance is just terrific

Despite its small-town Lancashire setting of hardscrabble pubs, lock-ups and secret wartime bunkers repurposed as marijuana farms, there has always been a touch of the surreal to Brassic. Over the course of five lairy seasons, the profane but sneakily profound comedy – centred on bipolar scallywag Vinnie (Joe Gilgun) and his found family of thrill-seekers and wheeler-dealers – has always been so much larger than life that it comes as no surprise that reality sometimes bursts at the seams. All the second-hand weed smoke probably helps.

So when A Very Brassic Christmas – the show’s first ever festive special – opens with a robed Joseph and heavily pregnant Mary seeking refuge for the night, the New Testament vibes are not all that discomfiting.

When Joseph knocks on the door of the nearest steading, it becomes clear where and when we are. The white-bearded misanthropic farmer Jim (Steve Evets) – who looks, sounds and curses like Bad Santa after a long bender – gives the expectant parents and their donkey both barrels. (“Take your sob story and fuck off!”)

Evoking the classic nativity and peppering it with swearing is a typically transgressive Brassic lark. But Gilgun and his co-creator, Danny Brocklehurst, clearly appreciate the uplifting power of Christmas spirit, and are keen to channel it in their own exuberant style.

In this jumbo episode, Vinnie is also obliged to knock on a stranger’s door. His perpetually horny GP, Dr Chris (Dominic West, literally phoning it in) is partying in the sun with his latest squeeze; he needs someone to check on his Aunt Edie (Imelda Staunton) after a fall. She might not approve of his neck tattoos but Edie realises the lanky dude on her doorstep could be useful around the house. Before long, Vinnie has moved in temporarily to help the retired teacher get through the Christmas period, which – being estranged from her family – she professes to hate.

Elsewhere, another nativity has been ruined. The primary school Christmas production – in which Vinnie’s son Tyler is well-cast as Herod – is at risk thanks to vandals who trashed the place. Vinnie, his beloved Erin (Michelle Keegan) and their layabout crew scramble to source replacement scenery and props so the show can go on. But after initial attempts come up short, they begin to consider more illicit options.

It is when the gang target the Winter Wonderland run by self-regarding entrepreneur and frustrated actor Dick Dolphin (Greg Davies, clearly having great fun) that Brassic locks into its usual madcap groove, particularly when Tommo (Ryan Sampson), Ash (Aaron Heffernan) and the rest of the crew don Christmas costumes to execute a heist plan.

Farmer Jim is desperate to be part of the action – surely a Santa lookalike could be useful? – but at first Vinnie is hesitant. “When have I ever fucked up one of your jobs?” wails Jim, the perfect cue for a quick-cutting montage of all the times he has derailed the gang’s blags.

The chaotic heist – which includes a surprisingly good impromptu rap – is the sort of caper this gifted ensemble could do in their sleep. But Gilgun and Brocklehurst clearly appreciate that the real steal was getting Staunton on board. There is a cheeky wink to her current big Netflix gig as she berates Vinnie’s naff attempts to kit out the three wise men: “That’s not a crown, it’s a plastic tiara!” She should know.

In a smart use of the extended running time, Edie – who has a bohemian past, some skeletons in the closet and an actual mummy in her loft – gets her own story arc. The awkward house-share scenes between Gilgun and Staunton are terrific.

Heart-on-sleeve motormouth Vinnie cannot help but chip away at Edie’s reserve, and the odd couple bond over strong joints and their similarly fraught family experiences. There is a wonderful, warming crackle in the contrast between Staunton’s innate poise and Gilgun’s loose-limbed Fido Dido energy. It gives genuine heft to what could easily have been a relatively throwaway Christmas cash-in. That’s classic Brassic.

• A Very Brassic Christmas was on Sky Max and is available on Now TV