Which? says a survey of 4680 of its members found that the big four high street banks - Barclays, HSBC, Lloyds TSB and NatWest - are trailing behind Internet and telephone banks for customer satisfaction.

Although 61% of those surveyed held accounts at the big four, the high street banks performed very badly in the survey. All four banks scored just two out five for customer satisfaction.

The Co-operative Bank's direct banking operation, Smile, came out top in the study, with 80% of current account holders saying they were "very satisfied overall" with the service. Smile was followed closely by First Direct, Cahoot, Intelligent Finance (IF) and Alliance and Leicester's Premier Direct offering.

Branch-based accounts offered by The Nationwide Building Society and the Halifax were also awarded 'best buy' status by Which?.

Commenting on the findings, Martyn Hocking, editor, Which? Money, says: "If you're still with one of the big four high street banks, then now's the time to move. Internet and telephone banks seem to treat their customers better and you can get much higher interest too."

The survey also found that Internet banking is continuing to grow in popularity, with about half of those surveyed now using online services, up from 43% in 2006. Nearly a quarter said they used Internet banking services at least twice a week.

But despite the growth in Web banking the vast majority of respondents - 90% - still visit branches, although the survey found that they don't go that often. Over half of those that still visit their branch do so once a month or less and they mainly go to pay in cheques, amend personal details, transfer funds and order foreign currency or traveller's cheques.

However study found that mobile banking is still a niche market, with just seven per cent of respondents saying they have used m-banking services.

Around half of those surveyed said they do use regular telephone banking services, but the study found big differences in the quality of services offered by UK banks. The only banks to gain top rating for their service were the Co-operative Bank and First Direct, while Abbey and HSBC performed particularly badly, says Which?.