Mis-selling scandals have failed to stop banks pressurising their staff into pushing products which may be unsuitable, Which? claims.
Two-thirds of bank staff with sales targets said they are being placed under more pressure than ever to hit them and almost half know colleagues who have mis-sold products just to meet their goals, the consumer group found.
The research comes as complaints about the payment protection insurance mis-selling scandal continue to surge beyond expectations, with the total bill predicted to reach around £15bn.
Which? said its survey of branch and call-centre staff at HSBC, Royal Bank of Scotland, Lloyds Banking Group, Barclays and Santander indicated that many workers are still being driven towards putting "sales before service".
Over a third said they are not comfortable with the pressure placed on them to push a product.