The food market in the UK is worth £100bn a year, according to Verdict. Non- food is worth £175bn. It doesn't take a genius to work out the maths - or why the supermarket giants are keen to expand ever further into non-food.

According to Mintel, non-food sales through grocery multiples rose 61% in the four years up to 2004 to a value of £12.8bn. The market is thought to have grown a further 6% since then. And it's no longer just a battle being waged by Tesco and Asda.

Sainsbury's is also stepping its activity up a gear and even the smaller players are scrutinising their space to see where they can squeeze a few high-margin non-food lines in.

Last week, Sainsbury's announced it wanted to generate £3.5bn of sales growth over the next three years, a third of which would come from non-food.

"We recognise it is an enormous opportunity for us," says a spokeswoman. "We have always said the most important priority was to get our food offer right because that is why people come to Sainsbury's. But we want to complement that with a good non-food range. That offer is currently underdeveloped."

The retailer is planning to offering a basics range and also an upmarket 'Difference by Design', echoing 'Taste the Difference' in food. The move, which would see its proportion of non-food sales to overall turnover rise from 15% to 20%, signals a challenge to Asda and Tesco who, with their offers of electrical goods, homewares and home entertainment products, have so far led the way. Even Morrisons is getting in on the act. Though it is still concentrating on its food operations, it is appointing a director of home and leisure.

As for smaller multiples and the independents, it would be wrong to suggest that they've completely ignored non-food. Many of the discounters make a big play of it, usually on a when-it's-gone-it's-gone promotional basis.

Some have a fairly high proportion of non-food. Joe Morris, retail director of TJ Morris, based in Liverpool and which has 140 stores mainly in the north, says about 30% of its sales are non-food.

"Space is always an issue with non-food but we try and squeeze it in," he says. "We have always stocked non-food but the growth has come from the homewares, toys and gardening and household goods we now buy directly from the Far East. Previously we would buy through an importer."

Malcolm Pinkerton, business information analyst at the BRC, believes non-food presents a major opportunity for smaller independents. "Smaller multiples need to do it and inevitably will," he says. "They won't be able to stock furniture and DIY but they can do DVDs and smaller electrical items."

Those that do not have the physical space to play with could explore the online potential as United Co-operatives and the Co-operative Group have done with Co-op Electrical Shop.

The key to success in non-food is as simple as providing the products people want to buy, says Richard Hyman, MD of retail research group Verdict.

He suggests smaller players should take a leaf out of Tesco's and Asda's books.

"Supermarkets have always stocked non-food items. In the 1970s they would stock car batteries and greenhouses. They seemed to take everything people offered from an articulated lorry and consequently goods didn't sell, " he says. "Now they have specialist management teams dedicated to non-food to get the offer right."

Not everyone is convinced non-food is a good strategy for smaller players. "If they had a few TV sets in the corner they would just gather dust," says Clive Black at Shore Capital Group. "The independent does not have enough space to effectively merchandise food never mind non food."

As more grocery retailers get into non-food, the question is: what impact with they have on the high street? Retailers such as WHSmith, Dixons, Argos and HMV have already been hit hard by the double whammy of the internet and supermarkets' incursion into their territory.

Ironically, the supermarkets' non-food push could breathe new life into the high street. Black predicts the emergence of a new breed of stronger niche retailers. "Over the next five to 10 years we could witness a number of independent specialists coming to the market."

Pinkerton agrees: "What supermarkets are doing is adding to the market, creating a demand for a new range of often less expensive goods. Other retailers are going to have to become more specialist to compete.the strategies

Tesco



Strategy: Stated aim to be as strong in non food as food. Sells its widest range of non-food in its Extra and dedicated non-food Homeplus format. Launched non-food online and catalogue service Tesco Direct last year

Weakness: Lack of space. Desperate to add to its Tesco Extra formats

Non-food sales: About 20%-25% of total

Asda



Strategy: Dedicated non food stores; nine Asda Living and a further four set to open. George brand to go on wide range of homewares. Aims to grow furniture online.

Weakness: Success of George in clothes not yet replicated with general merchandise

Non-food sales: About 15%-20%

Sainsbury's



Strategy: To grow non-food sales rapidly over the next three years. Half all new floorspace to be devoted to non-food

Weakness: Slow off the mark with non-food and playing catch up with Tesco and Asda

Non-food sales: About 12%-15%

TJ Morris



Strategy: Taking advantage of ability to source low-priced housewares and toys directly from the Far East.

Weakness: Space constraints

Non-food sales: About 30%