Supermarkets have a pretty strong selling point – you need food, credit crunch or not. But they are being squeezed from all sides.

On the one hand, suppliers are holding their own as they try to force through food inflation.

And in the shopping aisles, customers are voting with their feet, heading for the discounters Aldi, Lidl and Netto if they can't pick up bargains.

Supermarkets have already signalled their intention to meet the discounters head-on by dropping prices and expanding their budget ranges.

But it's what the supermarkets offer beyond food – non food – that will be the next battle ground. Leeds-based Asda, Britain's second-biggest grocer, this week launched a non-food website, selling 9,000 goods ranging from power drills to furniture and clothes.

It mimics Tesco Direct launched two years ago, which sells about 12,000 products online and about 7,000 in its 1,000-page catalogue.

Asda's 644-page catalogue is with the printers, and will soon be in stores to support the new website. Customers can initially order products online or by phone for home delivery. Store collection and in-store kiosks will follow.

According to one analyst, strong sales figures yesterday from Sainsbury's, showing like-for-like sales up 4.3 per cent, may be "as good as it gets".

But buried in that was a strong performance from "non-food" and clothing, which Britain's third-biggest supermarket feels has "enormous potential".

Sainsbury's has plans to follow Tesco and Asda's lead, with a similar initiative next year.

While home shopping is still very much a business in its infancy for supermarkets – Tesco expects Tesco Direct to make a £20m trading loss in the current financial year – the future has been staked out.

There have to be victims in this brave new world the grocers are branching out into. "It's going to add fuel to the fire," said Bryan Roberts, global research director at Planet Retail, who sees homewares, toys and clothing stores as most at risk from the supermarket expansion.

Toy-focused Woolworths and electrical retailer DSG have seen poor results in recent months, and Britain's biggest home retailer, Argos, faces a direct challenge.

Retail researchers Verdict estimate grocers already account for 11 per cent of Britain's £167bn non-food market and expect this to grow to about 13 to14 per cent over the next two years, helped by diverse strategies.

Verdict analyst Neil Saunders said: "If you have the choice of buying the same, or a similar, product and the grocer can give you a two-hour delivery slot and can get it to you the next day, and the other player can't, it's a bit of a no-brainer who you go for." The days of the pure food supermarkets are no more.

Scrabbling for that extra spend is what the supermarkets do best. Diversifying beyond the bricks and mortar of their stores into the higher margin world of online sales of toys, tools, clothes and furniture is the natural step.

Only Bradford's Morrisons – Britain's number four – is staunchly resisting the shift online. It has a website but no online sales, and while it offers in-store deals on computer games and DVDs, has no plans to move to the web.

"Morrisons has become famous for its fresh food offering," said a spokesman.

It's a bold stance to take, but time will tell how long it can swim against the tide.

If you have a view on this, feel free to contact Blackfriar at citydesk@ypn.co.uk