The figures were released in the Ombudsman’s annual report today for the year until 31 March 2012.

Advisers accounted for the smallest percentage of complaints and were down from 1.5 per cent last year, reflecting a decline in the number of investments and pensions complaints.

Over half of these complaints against financial advisers were upheld by the Ombudsman.

The total number of complaints received by the Ombudsman was 1,268,798, up significantly from 1,012,371 in 2011.

Some 65 per cent of these complaints related to banks, particularly regarding payment protection insurance.

Some 157,716 complaints related to PPI, 60 per cent of the Ombudsman caseload, up from 104,597 in 2011.

Almost half of complaints made to the Ombudsman were made by claims-management companies, 88 per cent of which related to PPI.

However, the Ombudsman said the total number of PPI cases brought to the Ombudsman by claims-management companies had declined from 76 per cent to 69 per cent, partly due to the work the Ombudsman had been doing on encouraging consumers to claim directly.

Natalie Ceeney, chief ombudsman, said the Ombudsman was working on making its decisions more transparent and helping financial businesses understand what the Ombudsman does.

She also said the Ombudsman would be working closely with the new Financial Conduct Authority.