(CNN) -- Helena Morrissey has seen a shift in the mindset of business leaders. Previously the idea of more women in the workplace was dismissed as "political correctness," but now she says the same people are asking how they can get the best candidates for the job.
As CEO of Newton Investment Management, Morrissey oversees around $50bn of funds under management and almost 400 employees. She's also one of the few female CEOs in the City of London.
The mother-of-nine says being passed over for a promotion after having her first child was "an eye opener," when bosses doubted her commitment. She now spearheads the 30% Club, campaigning for greater female representation at the top of British companies.
"If you look at the state we are in, the financial crisis, there is a strong argument that there is an identikit culture in lots of boardrooms; white, mostly men, same sort of age," Morrissey says.
Currently only around one in 10 board members in Europe's top companies are women. The figure is slightly better in Britain, where almost 15% of all FTSE 100 boards are now female. But British Prime Minister David Cameron says the country's economy is being held back by too few women in the key roles.
At a summit in Sweden on Thursday, Cameron said evidence showed there's a positive link between women in leadership and business performance.
This can be seen with Burberry -- which leads the FTSE 100 pack with three out of eight members of the company's board being female -- where despite the UK's retail downturn, the group recently reported strong sales.
"If you want to change the way business decisions are made and ultimately how shareholders receive returns, you need the best person for the job," says Morrissey. "Or a different sort of person than there was in the past."
Several European countries are adopting quotas for the number of women in the boardroom. Cameron says he's looking to countries such as Norway, which has spearheaded change in the boardroom, and has already reached its 40% mandate.
But Morrissey objects to the idea of set quotas, saying it is demeaning to women. "It suggests it's a numbers game and not about getting business results," she says.
Some businesses are setting their own goals, such as France Telecom Orange, which aims to have the same proportion of women on its boards as it has working in the company.
"I see this (as a) concerted effort, led by business, supported by government," says Morrissey.
CNN's Emily Smith contributed to this report