The firm surveyed over 1,200 adults and found 73 per cent of people did not think the FSA had been effective in standing up to banks in the run-up to the financial crisis.

Some 83 per cent of people said the regulator needed to have more power to force banks to change.

Only 36 per cent of people said the FSA had made sure banks had treated their customers fairly.

The majority of respondents said, however, that a financial regulator was needed as they did not trust the banks to regulate themselves.

Which? chief executive Peter Vicary-Smith said the Financial Conduct Authority would need to be tough on banks when it is implemented in the future.

The Financial Conduct Authority will be responsible for regulating conduct in retail and wholesale markets.

He said: “This is a once in a generation opportunity to get this regulation right. People are crying out for a strong financial regulator that fights on their behalf. The FCA has the potential to stand up for consumers’ interests but it will need to be tough and proactive.

“The new regulator must act to stop commission-driven sales, tackle poor products and should hand down fines and punishments that act as a real deterrent against bad practice by banks.”