Butter, eggs, cereal, fruit juice... and while you’re at it, why not pop a two-up, two-down terraced house in the shopping trolley?

It may seem barmy, but if you live in the North east of England it’s not as far-fetched as it sounds. Asda is providing estate agency services in 21 of its stores and is set to roll out 20 more this year.

So far, the supermarket has sold more than pound;1 million worth of property. Using touch screen terminals in-store, shoppers can check out the local housing market, arrange a viewing and, if they buy, a flat-rate 1 per cent commission fee is charged - undercutting high street estate agencies by up to 2 per cent.

This is just the latest venture by the big supermarkets to shake up Britain’s personal finance markets. And since Tesco and Sainsbury’s burst on to the scene in the mid-1990s, followed by Asda in 2003, they have certainly done that.

Capitalising on their trusted brand names and our flagging interest in high street banks, the supermarkets offer everything from bank accounts and credit cards to mortgages, pet insurance and over-the-counter car breakdown cover.

Bank accounts can be topped up at the checkout or customer service desks.

And loyalty points are offered as an additional bonus.

“They have got a captive audience,” says Andrew Hagger, a financial analyst with comparison website Moneyfacts. “What else do you do as you queue at the checkout? You either look at what the person next to you has got in their basket, or read the array of financial leaflets by the till.”

But just because your favourite supermarket has the best fruit and veg around, doesn’t mean the same goes for their personal finance deals, says Andrew. You still need to shop around. “The supermarkets are quite strong on things that are fairly simple to understand, such as credit cards and personal loans,” he says.

Tesco’s Bonus Mastercard and Sainsbury’s Bank Mastercard are among the top five best deals on the market at the moment, according to Moneyfacts. And the instant access savings accounts offered by both stores offer higher than average rates.

“It’s the emphasis on convenience, simplicity and value for money that has struck a chord with time-pressed customers,” says Monica McCormack of Tesco Personal Finance.

Taking on board concerns about supermarkets selling hefty financial packages such as mortgages, Tesco has launched a six-month trial of a mortgage advice service with mortgage broker London and Country so customers can shop around and compare deals with Tesco’s own range.

So, who knows? A shopping list of the future may well look like this: house from Asda, mortgage from Tesco, soft furnishings from Sainsbury’s. And don’t forget the champagne... but shop around first www.tescofinance.comwww.sainsburysbank.co.ukwww.asdafinance.com