Lloyds Banking Group has seen the level of customer complaints received grow by 14 per cent in the second half of 2010 alone, official figures show.
Between July and December 2010 the bank, which is part-owned by the state, saw the level of complaints rise from 288,717 for the previous six months to 329,761.
The disclosure of the figures is part of the Financial Services Authority scheme to make all banks reveal their customer complaints.
The bank cited payment protection insurance mis-selling complaints as a key reason for the surge in numbers of angry customers. In fact, the bank added that the level of complaints for non-PPI issues had fallen in the last six months of the year by 12 per cent.
The bank said that this downward trend demonstrated that it had got changes in its complaint-handling procedure right: "Our customers tell us the two areas we need to improve are the length of time it takes to resolve complaints and the perception that the bank is not taking sufficient ownership of them," said Martin Dodd, the customer services director of Lloyds. "We are committed to getting this right."
Other banks are expected to release their complaint figures this week. The results will be watched keenly by consumer groups.