Six months after the government ordered large firms to reveal their gender pay gaps, the majority have yet to publish their figures.
Charities, private and public sector employers with 250 or more employees must publish their figures by April 2018, in a bid to tackle workplace discrimination.
Only 85 of 90,000 companies required to publish their pay data have done so. There are concerns firms are delaying publishing to avoid negative publicity.
The business lobby group, the CBI, said: “Businesses have until April 2018 to publish their gender pay data. While some firms have published their gender pay gap already, many others are in the process.
“As with any new regulation, firms will want to make sure they get it right and will use the time available to them.”
Jane Gratton, head of business environment at the British Chambers of Commerce (BCC), said “many firms” were likely to be in the process of preparing the statistics.
“When all the figures are compiled, they need to be looked at in context. The government should publish sector averages so firms can benchmark themselves against others in their industry, and ensure they are doing all they can to attract and retain the vital skills women bring to the workplace.”
The companies required to comply with the new law collectively employ more than 15 million people, just under half of Britain’s workforce.
Minister for Women Anne Milton told the BBC it “is not an option, it is the law” for firms to reveal their gender pay gap.