John Lewis Christmas advert 2014: It's sickly and sweet but surprisingly potent

Sam is a cute little boy who has an even more adorable penguin friend, Monty.

They are inseparable, playing football and hide-and-seek together. But Monty is sad because he wants a "special friend". So on Christmas Day, Sam gives Monty the gift he has been dreaming of, a new penguin friend called Mabel, as a tremulous rendition of John Lennon's "Real Love" swells to an emotional peak – and a viewing nation dissolves in floods, then heads straight to John Lewis to buy their pre-lit paper birch Christmas tree for £125.

Now an annual event almost akin to Glastonbury and Wimbledon, the new John Lewis Christmas advert "breaks" today with the premiere of "Monty's Christmas", the £1m sequel to last year's equally heart-rending "The Bear and the Hare".

That woodland scene, accompanied by Lily Allen's "haunting" cover of Keane's "Somewhere Only We Know", is credited with helping boost John Lewis's sales by 6.9 per cent on the previous year. The retailer did not repeat last year's lavish London cinema screening launch, though, preferring to unveil the 2014 clip via social media instead.

This year's offering, created by the advertising agency Adam&Eve/DDB, does not stray far from a shamelessly sentimental formula. The two-minute "Monty's Penguin" clip evokes "the magic of make-believe at Christmas through a child's eyes", the retailer says.

No John Lewis festive film would be complete without a hushed, melancholic trudge through a popular song. After a nationwide search, the hand of fate has fallen upon Tom Odell, the Chichester singer-songwriter who can expect a chart-topping boost from his reworking of an overlooked Lennon song, revived by The Beatles for their 1995 Anthology collection.

The real message behind Monty's Christmas appears to be: "if you're looking for love and companionship. You can buy it at John Lewis." The narrative follows Monty and Sam taking bus rides and sledging in their local park. But Monty is sad when he spies a happy human couple and only perks up when he receives his present of a female toy penguin.

Behind the clip's heartwarming glow and the "Give someone the Christmas they've been dreaming of" strapline, the John Lewis advert signals the launch of a retail battle for "eyeballs" over the festive season. Burberry has delivered a pre-emptive strike with its "From London with Love" campaign, which features a 12-year-old Romeo Beckham, swaddled in a Burberry scarf and trench coat, playing cupid to a young couple. The advert has been viewed 2.3 million times online since Monday.

Waitrose, despite being part of the John Lewis group, is hoping to steal the "most talked-about Christmas advert" crown, with an emotive charity single, featuring community choirs and singers performing a version of Dolly Parton's "Try". Sainsbury's is expected to reveal an advert that focuses on the famous football match that took place between British and German forces during Christmas 1914, to mark the First World War centenary.

And so John Lewis, which recorded a 44.3 per cent online sales surge after its 2012 tale of a snowman making a perilous journey to buy a hat and gloves for his snow-woman companion aired, has been forced to up its game.

"Monty's Penguin", part of a £7m festive store campaign, has Hollywood pretensions. Monty and Mabel have been created using complex CGI technology "to look and behave exactly like real-life Adélie penguins".

The last people to see the television advert, after its merits have been thoroughly debated on Twitter today (#MontyThePenguin) will be actual television viewers. The full 120-second version will air on Friday during the first ad break in Channel 4's Gogglebox and will no doubt be chewed over by the series's couch potatoes the following week. If they're not reduced to a moist-eyed mess then Christmas is cancelled.