The City watchdog must name and shame the firms that are failing to treat their customers fairly over compensation for missold payment protection insurance.
The call came this week from Which? executive director Richard Lloyd, after the Finance Conduct Authority revealed that "there are still significant issues that need to be put right" among medium-sized lenders.
The regulator checked how 18 smaller high street banks, building societies, credit card providers and personal loan companies are dealing with the huge backlog of PPI complaints. Together, they account for around a million complaints, or circa 16 per cent of the total.
But the FCA has been forced to take enforcement action against one of the lenders over its poor handling of PPI complaints and warned that 12 of the 18 smaller lenders face further action.
Clive Adamson, director of supervision at the FCA, said: "We expect firms to deliver fair outcomes to PPI complainants. but our review found that some firms still have some way to go."
Richard Lloyd said: "This is further evidence that some firms are not dealing with PPI complaints properly and are fobbing off customers who have genuine complaints. People deserve to get back what they're rightly owed, with minimum hassle.
"We want the FCA to name and shame the firms who not treating their customers fairly and follow up with tough action, including heavy fines, against anyone found breaking the rules."
The FCA said the amount of PPI redress paid out in July was nearly £528m, up from £498m in June.
- More about: