Just 4 per cent of people said they would trust a supermarket to look after their money more than they would trust a bank, compared with 27 per cent who said they would trust a bank more.

A further one in five said they would not trust a supermarket with their finances at all, according to website moneysupermarket.com.

Supermarkets have made no secret of the fact that they want to expand further into financial services, with many already offering a range of products, such as credit cards, savings accounts, insurance and loans.

Tesco recently announced plans to create a full service retail bank and it re-named its financial services division Tesco Bank.

In his Government-backed review of the savings and investment industry Ron Sandler said people trusted supermarkets more than they trusted many traditional financial services providers.

But 41 per cent of people questioned for the research said they thought supermarket brands were expanding too much and should stick to traditional products, although more than a third of people said they were happy with the growth.

Kevin Mountford, head of banking at moneysupermarket. com, said: "Many people are naturally cynical about the expansion of large brands into new product areas, feeling that certain companies are getting a bit too big for their boots in taking on so many different industries all at once.

"However, in general the introduction of more competition within financial services should be seen as a positive move, especially after a period of consolidation.

"More competition generally heralds a better deal for consumers, and with that in mind we welcome any new entrants to the market."

One in five said they thought supermarkets offered better deals on a number of products, such as insurance and savings accounts, than high street banks.

But despite this, the vast majority of people said they were unlikely to take out a financial product with a supermar-ket.

One in four people said they would take out a credit card with a supermarket bank and 23 per cent said they would take out general insurance.

But only 15 per cent said they would be willing to open a savings account with a supermarket, while just 11 per cent would have their current account with one, only 10 per cent would take out life insurance and just 5 per cent would have their mortgage with a supermarket.