The number of complaints against the watchdog remained steady over the course of the year, with 246 received between December 2014 and 31 May 2015 and 245 between June and 30 November 2015.

The complaints comprised a total of 546 allegations closed, 47 per cent of which the FCA did not investigate. 

The regulator explained in its data bulletin: “This can be for a variety of reasons, including that the complaint is a general expression of dis-satisfaction where no misconduct has been alleged, or that the allegations are excluded, referred, deferred or outside of our scope.”

The FCA investigated 291 allegations, of which 58 per cent were dismissed and 42 per cent were upheld in whole or in part.

The Financial Services Act 2012 requires the FCA, the Prudential Regulation Authority and the Bank of England to have arrangements for the investigation of complaints against them. The FCA plans to continue publishing information about complaints it has received as part of its “focus to be a transparent regulator”, it said.

Last month, Andrew Bailey, the Bank of England's deputy governor for prudential regulation, was appointed as the new permanent CEO of the FCA after interim chief Tracey McDermott decided not to take up the role permanently.