Will the first gender pay gap reports really make a difference? 

Information on any bonuses paid also needs to be published at the same time for the 12 month period ending April 2017. However, there is no obligation for companies to explain the gender pay gap.

Emma O’Leary, employment law consultant for the business support group ELAS, said: "There are still approximately over 100 firms who are still to publish their data today. Those that have reported so far have revealed overwhelming gender pay gaps.

“However, as headline grabbing as that seems at first, it demonstrates the importance of companies publishing a report to go alongside the data which, in some cases, does explain why there might be a gap and could go some way towards watering down the initial shock of the statistics. With all that being said, the very clear theme we’re seeing here is that the gender pay gap does exist and there is still work that needs to be done in order to eradicate this antiquated inequality.”

Dr Sumita Ketkar, senior lecturer in leadership and professional development at Westminster Business School, asks if the reporting legislation has helped.

She said it has to some extent: “Frequent headlines about gender disparity in some of the long-revered organisations, both public and private, has undoubtedly been raising awareness about wage disparity between men and women. However, the six-key metrics under the reporting regulation still don’t reveal the full scale of the problem. After all, these are only some high-level indicators that require further investigation, which can only be undertaken by the employers themselves.

“What happens post the reporting is a bigger story to tell. What will companies do once they have published the gap?

Will there ever be an ‘ideal’ gap, will there be a 50:50 divide between men and women participation in the labour market? Will there be harsh penalties on employers who do have some gap? And what happens if a firm doesn’t do much to mitigate its gap in the subsequent year or after that?

“We seem to be organically moving towards a more egalitarian society where the ethical and moral case as well as a business case for gender equality is understood. Perhaps a wrap on the knuckles by the government, in tandem with a growing equality narrative from the public, will force employers to re-consider their gender pay figures.”