The total liabilities for interest rate protection products (swaps) mis-selling by the banks could rival that of the £22 bn the banks had to find as a result of the PPI scandal.
The exposure of Lloyds to this has been put at about £5 bn by the Independent  and other banks could be in the same boat says their report.
This could well hit the government's plans to return the Lloyds Banking Group to private ownership as well as being another blow to re-establishing trust in the UK banking system.
Commenting on these findings Charlotte Webster of Move Your Money said:
"This latest mis-selling scandal demonstrates that public-owned Lloyds remains right at the bottom of Britain's banking barrel. The mis-selling of swaps to SMEs is just another illustration of quite how unethical and self serving the bank really is.
Very disappointingly, it looks as if this could be another industry wide issue. Of all of our banks Lloyds is one of the worst performers for honesty and customer service, coming up last in 11 of 16 indicators on the Move Your Money Switching Scorecard.
This includes receiving over 2.5 million complaints in the last two years. It has already paid out or set aside more fine payments than any other British bank, and took over a third of the total compensation pot for the entire PPI mis-selling scandal. It's no wonder millions of people have had enough and are moving away from old school finance to banks and building societies that actually care about customers. In these changing times, you can find out more about how British banks are performing on our Ethical Scorecard."