The phrase Christmas in July no longer delivers the shock factor it once did:

despite the 24/7 stream of online news, the glossy magazines still work to advance print deadlines of several months. This fast-lane slow-lane information highway necessitates the somewhat anachronistic summer unveiling of Christmas merchandise to all media for public dissemination any time from now.

This year, the festive food retail market has polarised quite dramatically. As Tesco and Morrisons' sales ratings slip, the upmarket and budget chains are forging ahead. Which means arch top-end rivals Waitrose and M&S are going head to head, while casting a nervous eye over discounters Aldi, Lidl and Farmfoods, who are seeing the greatest collective surge in sales across the demographic sphere.

And so it came to pass that in early July, on one of the hottest days of the year so far, some of London's swankiest hotels opened their doors to a sun-tanned corps de presse to reveal various spectacular displays of goose, duck and turkey; lobster and smoked salmon on ice; and chilled and frozen festive desserts, all in the unlikely setting of trees, wreaths and baubles.

Waitrose went for noshtalgia with an Elizabethan feast of stuffed turkey breast rolled in old-fashioned butter muslin, a two-bird roast, a duck-and-gingerbread stuffed turkey. Its exclusive Heston range has a new multi-layered dessert, inspired by the chocolate bars of chef's childhood.

Meanwhile, M&S had an outstanding selection of new items such as a range of hand-plucked hung turkey, goose and duck; a pheasant, partridge and pigeon joint; a whole baked pear and Stilton pork pie; and as a challenge to Heston, a five-gold-ringed chocolate praline bombe.

It's easy to dismiss such decadence as heartless hype in the age of food inflation, welfare cuts and food banks. But the commercial reality is we continue to spend more on food and drink at Christmas than at any other time: last year saw a 3.9 per cent increase on 2012. Grocery sales are forecast to grow by at least another 1 per cent in December 2014.

Given the importance of online and print pre-publicity, retailers are competing on visual appeal as well as price and convenience for a share of the £19bn festive food spend.

Upping the ante in this most competitive of markets requires year-round research and development; retailers must keep improving their own offer while trumping the competition. I caught a glimpse of the hard work that has been going on behind the scenes for 18 months at M&S, and it's doubtless the same for the others. M&S new product development managers (including two highly talented Scots specialists in seafood and chilled desserts) have been travelling the world to source the latest trends and ingredients while pushing local produce.

The results include such delights as shimmered mousse dome desserts with Tahitian vanilla; a Brussels sprout juice; Tate & Lyle treacle soaked Scottish salmon; and a £350 Iberico ham complete with wooden stand.

For the moment, though, take a chill pill: you may look, but you can't touch until October at the earliest.