Nick Mohammed’s character Mr Swallow embodies some of the same contradictions as Tommy Cooper. His giddy, erratic demeanour on stage conceals a high-performance machine, in full view when he pulls off complicated magic tricks, feats of mentalism and even daring escapes, as in his 2016 show Houdini. 

You could say something similar about Mohammed’s tremendously scatty new West End Christmas show: uneven and unfocused, it still cannily hits all the beats required of a satisfying festive smash.

The premise is simple. Sorry, excuse me, the premise is extremely complicated. Mohammed’s nebulous alter ego Mr Swallow is putting on a musical version of A Christmas Carol that has been rewritten by his producer and co-star Mr Goldsworth (David Elms) to be about Santa Claus cancelling Christmas, with further alterations to the script having been made on a last-minute basis by Mr Swallow, and regular format-breaking interjections by Kieran Hodgson playing an actor called Jonathan playing Rudolf the Red Nosed-Reindeer, and Ghosts star Martha Howe-Douglas as actor/Christmas elf Rochelle, an excellent new foil for Mohammed. Suffice to say neither the audience nor the characters knows exactly what’s going on.

Up close and personal, the energy of the production just about pulls you through the multiple conflicting layers of reality that often threaten to overwhelm Mr Swallow, but this show retains almost no connection to the simplicity and moral power of the Dickens story, as becomes crashingly obvious when the second half opens by chaining together a song about being on vacation, a slapstick sketch about the Virgin Mary giving birth on the NHS, and a serenade to a turkey sung by Satan (that’s right, Satan not Santa). 

No idea is left on the table here, which is ultimately to the show’s benefit, but can leave your head spinning as you struggle to make sense of  what’s going on and what to expect next. Will it be Hodgson busting out an opera solo, an emotional wrecking ball of a song about the death of Goldsworth’s mother, or an animatronic shark fin accompanied by hula music? Any attempts to follow a coherent narrative should be left at the door.

In a quintessential Mr. Swallow move, what must be Mohammed’s biggest ever budget has been spunked entirely on an incredibly beautiful and elaborate set, while he retains only three other cast members, and his ghosts of Christmas are mostly the same guy dressed in the same Zara Home bedsheet over and over again. 

The show makes a virtue of these limitations, even if they now feel largely self-imposed in the glitzy environs of London’s newest and sleekest West End theatre. Alongside set designer Fly Davis, special mention should be given to composer Oliver Birch, who furnishes the production with some great Wicked-esque Broadway ballads as well as a couple of numbers that might even get toes tapping.

Its wandering comedic eye notwithstanding, the script hits way more often than it misses, throwing out gags like sparks off a Catherine Wheel, and Mohammed fully commits to a chaotic, all-singing all-dancing performance that guarantees some degree of fun whenever he’s on stage, more than justifying his role as the anchor of a big budget West End show. 

As a crowd-pleasing, energetic and genuinely festive Christmas offering, it’s 50 times better than your average panto – if that’s not damning with faint praise.

• A Christmas Carol(ish) runs at @sohoplace until New Year's Eve. Tickets