With a month to go before the deadline, only a fraction of the companies expected to produce gender pay gap reports have so far done so.

The government said that around 9,000 organisations were expected to produce reports when it announced the new policy. New research, however, reveals that just 1,442 of those have produced their gender statistics, and one-fifth if them are public sector organisations.

The research, undertaken by the Financial Times, shows that the average gender pay gap for private sector companies reported so far is 7.3%.

In February, Barclays International, the investment bank, revealed in its annual report an average gender pay gap of 48%.

In the annual report, the bank said it was continuing to “focus on ensuring there is no bias in the hiring, promotion, development and retention of women at Barclays.”

In December, oil giant Shell published a pay gap of 22.2%. SSE was the first FTSE 100 company to reveal pay gap numbers, reporting a median figure of 19.3% for 2016-17.

In an article for the The Conversation website last year, Chris Dawson, an associate professor in business economics at the University of Bath, wrote that his research showed that women are generally more pessimistic than men at work and this affects their pay because they tend to be “more generally satisfied with their work and income.”

In short, women are “predisposed to underestimating themselves and their labour market prospects.”

Dawson wrote: “This is a worrying state of affairs. We tend to search for new jobs when we feels that some aspect of our current occupation, such as pay, can be improved upon. But if we are satisfied, we stay in that job, we don’t negotiate and we don’t ask for that promotion.”

He adds: “It is difficult to know how laws and policy makers can solve this pessimistic female outlook, since personality traits tend to be established and fixed early on in pre-adult life. But perhaps one step in the right direction would be for employers to adjust their recruitment and promotion policies, by pulling up women with potential instead of waiting for them to come knocking.”

The FT also reports that 3% of companies say they have no gender pay gap, a fact the paper says in a headline is “implausible”.

The deadline for companies to produce gender pay gap reports in 4 April.