One in five companies of the FTSE 350 have no women or just one woman on their board, a statistic that has prompted action from the Investment Association.
The trade body, alongside the Hampton-Alexander Review, has written to these 69 companies, outlining concerns about the lack of gender diversity on their board.
The letter asks companies to outline what action they are taking to make progress, and to ensure they are meeting the Hampton-Alexander targets of 33 per cent of women on their board and leadership team by 2020.
In February 2016, the government appointed Sir Philip Hampton and the late Dame Helen Alexander to chair an independent review to ensure women at the top of business are recognised.
The letter follows the announcement in February that the Investment Association's voter information service will give a 'red-top', its highest warning level, to so-called "one and done" companies who have just a single woman on their board, it stated.
FTAdviser reported in February that HM Treasury will be looking to assess whether firms have made sufficient progress towards diversity.
While the business case for diversity was irrefutable, women still only made up a small part of most executive committees, John Glen, economic secretary to HM Treasury, pointed out at the time.
This was despite the government's Women in Finance charter, which is designed to promote gender diversity. More than 330 financial services firms have signed up to the initiative.
According to Chris Cummings, chief executive of the Investment Association, investors have been consistently clear that they want to see greater diversity in the boardroom, so it is "totally unacceptable that one in five of the UK's biggest companies are falling so far short".
He said: "Companies must do more than take the tokenistic step of appointing just one woman to their board and consider that job done.
"There is also compelling evidence that boards with greater gender balance outperform their less diverse peers. These companies must up their game and explain clearly how they are planning to meet the Hampton-Alexander targets, or risk investor dissent at their annual general meeting."
Sir Philip, chairman of the Hampton-Alexander Review, noted that most companies have made great progress in gender diversity in their boardrooms and senior executive leadership.
He added: "But there's a surprising number of boards with just one woman, which looks more like tokenism than diversity.
"It also does not reflect the population of very talented women capable of making great contributions in boardrooms."
Labour MP Rachel Reeves, chairwoman of the Business, Energy and Industrial Strategy select committee, argued that it is clear that some old-fashioned attitudes to the role of women in the workplace still linger in some of the boardrooms of UK's biggest companies.
She said: "The low numbers of women in executive positions can only hinder progress: gender pay gaps are highest in sectors with some of the lowest numbers of women executives.