I have a confession to make: I shop in Tesco. It’s a habit I’m trying to break but I know I’m not the only one surreptitiously slipping into the store on Portobello. But next time you head there, promise you’ll take a detour via Jasmine Guinness’ new toy shop Honeyjam and remind yourself why perhaps you shouldn’t be giving all your money to that supermarket opposite.

Set up eight months ago by model and heiress Jasmine Guinness and her childhood friend from Ireland, Honey Bowdrey, Honeyjam is a nostalgic reminder of toyshops that used to exist before little Asbo Alfie turned to PlayStation and gun crime. Such as Tiger Tiger on the King’s Road, now sadly extinct. ‘Tiger Tiger was our inspiration. A shop so packed full of stuff that would mesmerize us when we were little,’ Jasmine tells me as we chat over tea at her shop counter. Jasmine, 30, who married long-term partner Gawain last summer, felt their kids, Elwood, five, and Otis, one, were missing out on just such a childhood experience. Fortunately, Honey felt the same, so Honeyjam was born.

With perfect timing to illustrate the point, a mother brings in her young daughter, who’s clutching a piece of paper. ‘Hello Maia,’ says Jasmine. ‘What have you got there?’ It’s a pre-prep hand-scrawled competition entry form. A chance to win a family barge holiday from toy brand Sylvanian Families, which celebrates its 20th anniversary this year. ‘Let’s hope we win,’ says mum, chirpily. ‘Although,’ she confides, ‘I think I’d rather just take the toys over the barge trip.’ It seems there is a limit to this vicarious childlike excitement after all.

Fluffy, anthropomorphised, woodland animals aside, HoneyJam is crammed to the rafters with some really breathtaking toys that would set even the most jaded adult’s imagination alive. Take the Grove team for instance. We cooed lots: ‘Look, there’s a three-foot unicorn! Oh, and check out the miniature theatre set next to the flamingos, and the cutest miniature Aga (‘A firm favourite with the little boys!’ Jasmine tells me). In fact, we’re so enraptured by the incredible treasure trove of gubbins, that we forget that we’re meant to be photographing our star Jasmine.

Jasmine apologises about her big hair. Yesterday, she mentions, she was modelling fashion for British Vogue with photographer Patrick Demarchelier; today she’s Grove’s cover star. Vicky, our photographer, grimaces – aware she’s following in the footsteps of just about one of the world’s best fashion photographers. With Demarchelier in our sights, we breezily tape a sheet of pretty butterfly-print gift wrap to a wall and plonk Jasmine in front of it. Smile! The self-confessed ‘mad woman in a toy shop’ is once again a model.

As a stream of excited families pour through the shop, we’re a far cry from the world of high fashion – this is more about toy models than size-zero ones. What does Jasmine make of the perennial hoo-ha about too-skinny models? ‘Some people are naturally skinny and some people want to be thinner – it’s human nature. We always want what we haven’t got. Of course there is pressure on models, but it comes from all sorts of places, not just one. What about magazines that show pictures highlighting stars’ cellulite? Shouldn’t women with curves be put on a pedestal too?’

But, these days, Jasmine’s more concerned about small businesses than small models. Having lived in the area since the age of 15, she passionately believes in supporting the independent retailers over chains. ‘One woman came in and exclaimed to us: "Another toy shop on Portobello Road!" People think that any new shop that opens must be part of a chain or threatening the local businesses. But after the fabulous Barnett’s closed down last year, we’re the only toyshop on the road, which, in an area with so many families, is very sad.’

Portobello is ironically a victim of its own success – it’s attractive to the chain businesses simply because the touristaphobic locals, who live there, and the tourists, who wish they did, have money to burn. And why do the tourists continue to flock here? Any local who’s been asked the question ‘Donde esta el Travel Bookshop?’ knows they’re not here to shop at Tesco. But we locals do.Jasmine explains: ‘The best way to support the independent trader is to shop at their shops and not in big faceless businesses that focus on profit margins, not customers.’

A view echoed by staunch small-shop campaigner and local resident David Cameron in a recent newspaper column: ‘There’s a simple rule when it comes to local shops: use them or lose them.’ With their wise words ringing in my ears, I pop out from Honeyjam to grab a coffee and head to a local cafe.

The campaign is gaining momentum and local retailers are starting to recognize the need for mutual support. ‘When we first opened, we felt very much involved with the local culture,’ Jasmine says. ‘Stallholders were really friendly and brought us bottles of wine.’ A sweet gesture or a desperate search for solidarity? One only has to look down the road from Honeyjam at the looming facade of Tesco, the shiny signs of Star(mega)bucks and Café Cost-you-an-arm-and-a-leg to sense the potential for this David and Goliath battle to prove explosive in such a competitive stretch of road.

Even Jasmine’s mistakenly been on the receiving end: ‘In the first few weeks a few people came in and shouted: "We’re not shopping here! We’re against all the chains!" But we’re not a chain! Our online shop will come next so we may never need to open another Honeyjam store.’ For now, eco-friendly Jasmine, who even has a wormery at her home, is content with small-scale changes: ‘Next we’re planning to put green stickers on all our eco-friendly or sustainable products.’ A few weeks later, I’m having lunch at a cafe in the Portobello area. ‘This place is new,’ I say to my friend. ‘Oh, don’t you know?’ she says. ‘This used to be the most brilliant toy shop. Barnett’s, I think it was called.’

Happy Vegetarian Falafel, a stall on Portobello Road next to Snappy Snaps – the best falafel in town.

Essenza, 210 Kensington Park Road, W11 (020 7792 1066) - for the most delicious Italian food and child friendly environment.

Mike’s Café, 12 Blenheim Crescent, W11 (020 7229 3757) – for a superb fry-up and a strong cup of tea.

Harper and Tom’s, Elgin Crescent – for an amazing choice of rare and wonderful flowers that don’t cost the earth.