With just three months to go before the deadline for publishing gender pay gap reports, more than 90 per cent of affected companies have yet to comply with the new rules.

Charities and private companies with 250 or more employees must publish their gender pay gap calculations by April 4. For public sector bodies, the deadline is March 30. Yet according to the latest data, just 502 companies out of an estimated 9,000 affected firms have so far published the figures.

A new RSM survey of middle market businesses conducted by YouGov found that while 77 per cent of businesses said they had already published or were on track to publish their gender pay gap report on time, one in ten said they would be unable to meet the deadline.

Kerri Constable, a senior consultant from RSM’s HR consulting service, said: "The current level of compliance with the gender pay gap rules is very low but this is likely to ramp up considerably as we get closer to the deadline.

"However, these figures reinforce our concerns that there are many companies struggling to complete their gender pay gap calculations, partly as a result of difficulties with manipulating the data from payroll systems.

"Many employers are also using the remaining time to develop the right narrative to try and mitigate any reputational risk - both internal and external.

"We also suspect that many firms are playing a wait and see game so they can see how competitors are presenting their own findings.

"It would be wise for employers to remember that gender pay gap reporting is an annual requirement and every year progress will be expected. It’s therefore crucial for all affected companies to develop action plans to demonstrate their commitment to continually closing the gap."