The Government has written to the country's top company bosses urging them to increase the number of women on their boards.
Business Secretary Vince Cable and Home Secretary Theresa May sent letters to chief executives of firms in the FTSE 350 highlighting the business case for gender diversity on boards.
Firms were encouraged to follow a recommendation from a recent report by former trade minister Lord Davies of a September deadline to set targets for increased gender diversity on their boards, with a suggested minimum figure of 25%.
"Since Lord Davies reported, a number of companies have committed to taking action, and there has already been a strong improvement for FTSE 100 companies in particular," said the Government'sletter.
"The rate at which women have been appointed to board positions has significantly increased and the number of all-male FTSE 100 boards has dropped sharply, from 21 last October to 14 this month.
"We have been very pleased to see such a positive response from the corporate sector and we would encourage you to build on this by setting and developing targets and strategies, in order to effect the necessary change through means best suited to your own circumstances.
"There is a strong business case for increasing the proportion of women on boards and there is increasing evidence that diverse perspectives are critical to good governance."
Lord Davies will reconvene his steering board later this year to consider progress against his recommendations.