Guinness exhumes the ghost of Christmas past for its festive ad, via a jingly cover of Bing Crosby’s ode to difficult travel conditions.

Ostensibly aspiring to a monochrome holiday, the commercial is instead soaked in the murky brown tones in which your bathroom tends to get painted if you drink too much of the stuff.

There’s probably room for a booze to take ownership of Christmas in the way Coca-Cola does for soft drinks - at least until Asti Spumante belatedly gets its 1980s mojo back.

After all, if you can communicate the concepts of charity, goodwill to all men and the Immaculate Conception rolled together in a single carbonated beverage, doing it with something that gets you drunk at the same time should be a doddle.

And unexplained pregnancies after a night on the Guinness are nothing new.