Increasingly, as the issue takes center stage, companies are being pressed to publish their own reports on how much they pay each sex. U.K. businesses that have more than 250 employees are required legally to make their gender pay gap data available to the public by April.
One of the latest to disclose its figures was the Royal Bank of Scotland (RBS), whose chief financial officer made clear Thursday that more needs to be done to combat gender pay disparity.
"I think what it reflects is a lack of progress on senior women [into] positions in the bank, so about 37 percent of our top managers in the bank are female. We need to improve that," CFO Ewen Stevenson told CNBC in an interview.
When it released its annual report in February, RBS revealed that it paid women on average 37 percent less than men, with the company saying the pay gap reflected an under-representation of women at senior levels, which was "not a satisfactory position" in its view.
"We have a positive action approach in place, tailored by business, according to the specific challenges they face. As we continue to increase the proportion of women working in senior roles, we expect our gender pay gap will lessen," the lender's report said.