27/03/2014 04:33 GMT | Updated 26/05/2014 06:59 BST

Workplace Culture Must Change if Women Are to Reach the Top of Our Biggest Companies

On Wednesday, I was at Barclays UK headquarters in London where I was speaking at the annual launch of Lord Davies' and Cranfield's Women on Boards progress reports.

It's great news that we are on track to meet our target of 25% of female appointments to the boards on the FTSE 100 by 2015. And it's even better news that this is happening not because of legislation or Government quotas but because business leaders are recognising that it is the 'right' thing for their business to recruit the 'right' person.

Quotas are not something this government supports; women want to reach the top on merit and be respected when they get there. Not simply reaching the top because a box needs to be ticked.

Good progress

We have a lot be proud of when it comes to gender equality and there are many signs that show how much progress has been made. Over two thirds of working age women are in work - more than ever before; nearly 60% of new graduates are now women, along with over 50% of new postgraduates.

Government action

Academically women are proving that they are on top. They don't need special treatment. They just need an equal playing field.

As I have said before, the workplace was designed by men, for men. The Government is playing its part too by helping to modernise the workplace. We've introduced shared parental leave, flexible working and childcare tax provisions and we are taking firm action in response to the recommendations of the Women's Business Council.

However, we still have much more work to do. I am clear that legislation and government intervention is not the key to driving this change. Instead, the mind-set of corporate culture needs to catch-up with today's society. So, if girls and young women are out-performing men throughout the education system; why are they not equally represented up through organisations, and rising to the top?

Gender Pay Gap

New analysis of the gender pay gap sheds some light on this question. It shows the full-time pay gap for women narrowing significantly over time as women's education outcomes have improved and their aspirations have risen. So much so that the pay gap has virtually disappeared for women aged under-40.

And it also shows a clear cohort effect, whereby the pay gap falls first for the younger, and then older, age groups. This suggests that the end of the full-time pay gap between men and women could be in sight.

But that's only half the battle, because when you look at the overall pay gap, including those who work part-time - 90% of whom are women - we start to see much more significant gaps. Why is this?

I strongly believe it's because the workplace culture is still based around the 9-5 job, which means that we devalue anything but a stereotypical approach to work - to the extent that the average hourly pay for someone working part-time is £5 less than someone working full-time.

In my experience part-time workers are just as effective as full time workers. But the perception is that atypical working - including part-time work - can damage your career prospects. This penalises women - and mothers and carers in particular. But it also penalises our economy, when so much talent is suppressed by outdated attitudes and outmoded practices.

Business leaders need to take action

So I'm urging business leaders to take action. The simple truth is we need fewer than 50 more women on FTSE 100 Boards to reach the 2015 target, but crucially we need to see many more women supported to climb up the ladder behind them. There is a prize to be had by those Boards and those businesses, who get this right.

It's only by working together to drive forward this culture change that we will truly see parity for women in the workplace and fully reap the economic benefits that will come with this.