Nearly half of all bank customers would be happy to accept lower interest rates if it meant their bank invested more ethically, according to a new survey.

Some 40% of people said a healthy return on their savings was less important to them than ensuring their money was invested in worthy causes. A further 5% said it was the most important factor when choosing a bank.

However, banking experts said the good intentions revealed in the research by Which? Money magazine had not necessarily led to a major change in banking habits among consumers.

Mark Howland, head of marketing at Charity Bank, a non-for-profit bank, agreed: "Although there seems to be a definite appetite for ethical banking, at the moment we don't see anything equivalent to, say, the fair trade phenomena sweeping the industry."

In spite of this, Mr Howland said Charity Bank had seen deposits rise from £1.6m to £34m since its inception five years ago.

Ethical consumers
A number of leading financial firms have adopted schemes catering to ethically-minded consumers in recent years.

But Which? warned customers that the amount invested by firms in charitable causes could vary widely between them.

The American Express Red card gives £1 in every £100 to support Aids causes, whereas after an initial donation of £20, the MBNA Childline card gives only 15p for every £100 spent.

Which? was also careful to point out that banking ethically did not necessarily mean receiving a lower interest rate. Smile, the internet banking operation of the Co-operative Bank, offers a best buy current account, while maintaining an ethical investment policy, the magazine said.