The City watchdog is currently reviewing 172 responses to its Call for Input on the Duty issued in July, says its chief operating officer Emily Shepperd.

Shepperd said: “When we feed back next year, the aim is to address areas of duplication, confusion or over-prescription which create unnecessary costs for business while at the same time demonstrating it is possible to pursue market growth through sustained consumer benefit.”

She was speaking at the UK Sustainable Investment and Finance Association Leadership Summit in London today.

The regulator introduced the wide-ranging guidance last July, which requires firms to produce documentation to show that they are treating customers fairly.

It covers the whole of the UK’s 60,000 regulated financial firms, including the mortgage industry’s roughly 100 lenders and 18,000 brokers and broker firms.

Shepperd said that the measure is part of its plans to support its new secondary objective, introduced last year, to support the international competitiveness and growth of the UK economy.

She said: “The Duty, alongside our work on sustainability policy and market reforms, are examples of how we are furthering our primary objectives.

“All are timely and salient examples of how we want to lay the tracks and build the infrastructure in a way that furthers our secondary objective.”

When the measure was introduced last summer the watchdog said the guidance would “fundamentally improve how firms serve consumers” by setting out “higher and clearer standards of consumer protection across financial services”.

The measure is also aimed at ending “rip-off charges” and making it easier for customers to switch products.

The regulator wanted firms to more clearly explain their products “rather than burying key information in lengthy terms and conditions”, and offer more support to vulnerable customers, such as pensioners or those under financial stress.