Britain's top firms are suffering from a "diversity deficit" which threatens the country's domestic and international economic competitiveness, a new study claims.
The analysis of 10,000 FTSE 100 executives found that a "glass ceiling" is still in place with only a dozen out of the 289 top posts of chief executive, chairman or chief financial officer held by women, and just 10 by ethnic minorities.
More than half of the top stock market-listed companies have no non-white "leaders" on the board and two-thirds have no full-time executives from minority groups at board level, according to the study for executive recruitment consultancy Green Park.
Shadow business secretary Chuka Umunna said the research showed an "undeniable and unacceptable" situation and warned a future Labour government could, if elected, consider introducing boardroom quotas.
Former Equality and Human Rights Commission chairman Trevor Phillips, who carried out the study with King's College London academic Professor Richard Webber, said: "In the past decade, there has been a growing consensus that our business elite is simply too narrow in its outlook, too prone to a herd mentality and just not switched on enough to the 21st century world.
"Our new analysis backs this up.
"As China grows to be the largest consumer market in the world, and as the United States becomes a majority-minority society, the fact that two thirds of our biggest companies have all-white executive teams - and apparently not one person of Chinese descent - should set off a big red flashing light that we aren't equipping ourselves to compete in these markets.
"And as women become more important consumers domestically, it's self-defeating that they remain junior partners at the top of our economy.
"The fact is that if we're going to earn our way out of the recession, we just can't afford to be saddled with a diversity deficit this big."
The Green Park Leadership 10,000 used computer software to analyse the backgrounds of Britain's most top business executives, including gender and ethno-cultural composition, looking at 15 business sectors.
It found that sectors which had a good gender balance - like utilities - had less ethnic balance and vice versa.
Women and minority leaders feature "disproportionately" as non-executive board directors, which the report claims gives them less influence than their overall numbers suggest.
The research claims women occupy about one in four of the so-called Top 100 positions across FTSE 100 companies - leaders of minority origin account for just under one in seventeen.
Mr Umunna said: "The continued existence of a glass ceiling for women and ethnic minorities in our boardrooms is undeniable and unacceptable.
"Whilst advances on non-executive appointments in recent years have been welcome, progress on executive positions has been lamentable.
"It is clear there is a pipeline of women and ethnic minority candidates, achieving the highest qualifications, who are available for the top jobs and merit appointment, but not nearly enough of them make it through.
"If we do not see enough progress on increasing diversity in our boardrooms, we could consider introducing more prescriptive measures, such as quotas, in a future Labour government."