Lloyds Banking Group received the largest number of mortgage-related complaints during the second half of 2010.

Analysis of data published by the Financial Ombudman’s service shows that 663 new complaints were made against Lloyds Banking Group.

Lloyds Banking Group also received the largest number of total new complaints across FSA-regulated areas with 12,234 cases between 1 July and 31 December.

In the second half of 2010 the ombudsman service upheld an average of 53% of complaints in favour of consumers, compared to 44% in the first half of 2010. Across the 162 individual businesses included in the complaints data, the uphold rates varied substantially between 5% and 95% upheld in favour of consumers.

Which? chief executive Peter Vicary- Smith, said: “These figures reaffirm the need for a fundamental overhaul to the way many banks pay their staff. When bonus structures reward staff for selling products which may be unsuitable is it any wonder that we are seeing this level of complaints?