Payment Protection Insurance continues to top the financial Ombudsman's product complaints list, attracting 11% more claims in the three months to 30 September versus the previous quarter.
PPI gripes made up 45% of the FOS' workload in Q3, up from 34% in the previous quarter.
Current accounts were ranked a distant second, with 11% of complaints, followed by credit card accounts with 10%, and mortgages at 4%.
In 2009/2010, 49,196 complaints were referred to the FOS regarding PPI, with 90% being upheld in the complainant's favour, while more than one million complaints have been made to firms.
The FSA has clamped down on PPI selling with new handbook guidance to ensure complaints are handled properly and redressed fairly where appropriate.
However the British Bankers' Association's has said it will launch a judicial review of the new measures.
In July this year Lloyds Banking Group stopped selling the controversial product on loans, credit cards and mortgages, after declaring the product no longer "economical" for the business.
It follows a landmark decision last October, when a county court judge ruled £8,000 worth of credit card debt was unrecoverable due to the ‘unfair' way in which PPI was sold with the product.
He ruled credit card provider MBNA could not demand repayment because, at the time of purchase, it failed to disclose to the customer it would receive regular commission payments from the insurance provider, ITT London and Edinburgh, a subsidiary of Aviva.
Since then complaints against the product have soared.
Third day of election campaign
The chairman fears investors could think the regulator endorses passives
Calls on advisers to use stats to promote protection
Labelled a ‘stealth tax’