Carolyn Fairburn, Director General of business group, the CBI, said that the issue of diversity needs to run right through companies and has called for a new voluntary target of 25% for female senior executives in major UK companies.

Speaking recently at an event hosted by law firm Latham & Watkins, Fairburn had been asked to speak about women on boards of companies but she argued to achieve more executive directors there needed to be promotion and support of women throughout the company so they were viewed as future leaders of companies. Currently the change taking place in respect of the appointment of female chief executives and executives is still too slow she said.

"Today, there are just nine more female executive directors on FTSE350 boards than in 2010. While the number of female chief executives has barely moved – 5 in the FTSE 100, the same as 5 years ago."

So while she welcomed the Davies target that 25% of board positions are held by women was met last year, this was she said through their appointment as non-executive directors

"Non-executive directors and even chairmen are part-time. They attend between 4 and 10 board meetings a year. They approve strategy, are guardians of values, challenge decisions and help manage risk. These are very important roles. But they are not running organisations on a day-to-day basis.

"They are not hiring most of the people, taking daily decisions, shaping and defining strategy, forming cultures and habits through their everyday choices and the examples they set. This is the job of executives – the sleeves-rolled-up leaders in our society. And the truth is we just don’t have enough women who are executive leaders in the UK."

Fairburn welcomed the announcement last October by the Minister for Women and Equalities Nicky Morgan MP that she would be launching a new review focusing on how to achieve more executive directors and felt this voluntary target with focus the minds of business leaders on how the culture of organisations can be changed so that women not only rise up to be executives but remain there once they have been promoted rather than leaving. While some sectors still struggle to attract women into them others struggle to retain women she said.

"I have many friends who have succeeded in managing family and work successfully, but in the end have decided they just don’t want to go for the very top jobs. They are instead choosing to stand down and contribute in their communities – at schools, charities – or to take non-executive roles instead. And brilliant they are at it too. As a result many of our firms are seeing an exodus of senior women."

She said, "Too much of UK business is still geared up for men, in terms of its social habits, its small talk, its clubbiness. Women can look at this world and think – that doesn’t feel fun, it doesn’t feel as though I fit, it isn’t for me.

"As I say, these are complex and subtle issues. But unless we spend as much time thinking about the sticky floor as the glass ceiling, and about what is affecting the choices women make, it will be hard to make progress."

Fairburn said that UK business would be more successful and productive if the changes were made and companies were made up of a more diverse group of executives. She said McKinsey had analysed 366 quoted firms and found that companies in the top quartile for gender diversity are 15% more likely to have financial returns above the national industry median.

So she urged change throughout companies and more widely "Let’s turn our attention to the CEOs, the CFOs, the heads of operating divisions, the managing directors, the Director Generals and Permanent Secretaries in government departments, our ministers of state. And for the professional services world where I spent several years of my working life and where many of you work today, to the partners and senior partners who are running the show."