New figures show 50,639 new PPI cases were lodged between July and September this year, an increase from 42,401 over the previous quarter. This rise may be partly attributable to the Ombudsman’s new campaign featuring Arnold Schwarzenegger.

Caroline Wayman, the chief ombudsman, said there had been a “significant increase” in the numbers of people contacting the ombudsman about PPI over the last quarter.

The second most complained-about product over the same period was current accounts, which attracted 4,497 complaints.

Self-invested personal pensions (Sipps) also had a difficult run, with complaints looking likely to beat last year’s total. In the third quarter, the Fos received 1,025 new cases about Sipps. There were 1,493 new cases for the whole of 2016/17.

However, the number of cases upheld has declined for both PPI and Sipps. Only around 4% of PPI cases ever reach the Ombudsman, much lower than for other financial products, suggesting companies have got better at resolving them themselves. Payday loans had the highest number of complaints upheld, while packaged bank accounts had the lowest.