How well-paid women earned the chance to be breadwinners

Her husband, Colin, was a self-employed electrician, and she had

planned to take at least six months' maternity leave before returning to the law firm part-time.

However, shortly before the baby was born, the property market crashed and Colin, who had relied on contracts with major housing developers, suddenly found himself with little work.

The ensuing recession hit the couple's joint income hard and they decided that Caroline, who had the potential to earn more money as a lawyer, would go back to work full-time, leaving Colin holding the baby.

Similar conversations have been had in households up and down the country as the traditional balance between male and female earnings continues to shift.

According to the Women and Work Survey 2010 published today, almost half of the 2,000 females questioned were either out-earning their partners (30 per cent) or earning just as much (19 per cent). One in 10 already had a house husband and many predict that figure will continue to rise over the next few years.

"We're in the middle of a huge social shift," says Jane Bruton, editor of Grazia magazine, which commissioned the survey. "One possible explanation is the recession tended to affect men much more so than women.

"Women are increasingly earning as much or more than their partners and many of these women get a great amount out of their working lives. They're not working because they have to, they're working because they want to.

"For these high earners, it often makes more sense if their partners take on a greater domestic role. Of course, there are going to be mixed feelings about this, but it is definitely something that is becoming more accepted. Couples no longer feel bound by the traditional roles which restricted their own parents or grandparents."

The emergence of what Jane Bruton likes to call the Mrs Bigs would have been unthinkable a couple of generations ago and the Grazia survey comes on the back of further research which earlier this year found the number of stay-at-home fathers had risen 10-fold in the last decade.

When asked, the vast majority of couples admitted the decision had

solely been down to the woman's ability to earn more.

It's all a far cry from the 1960s, when just four per cent of women earned more than their partner, but in the last 50 years greater educational opportunities – women aged 30-34 are now more likely to

have a degree than men – have finally impacted on the workplace.

"The idea that men see themselves as breadwinners is collapsing," says a spokesman for the Fatherhood Institute think tank. "Since the 1970s, men have become far more egalitarian and the number who want to get off the career ladder and spend more time with their children has gone up.

"Figures from the Office for National Statistics show the number of men not working so they can look after their children has risen by 80 per cent in jut 15 years. In 1994, there were 120,000 men who described themselves as stay-at-home fathers. Today there are 214,000. Men are becoming aware that they haven't had it all."

However, as with every generational shift, there are downsides and with more and more mothers going back to work full-time and of their own free will, it seems a new battleground is emerging. The overwhelming majority of working mothers told Grazia their colleagues without children resented the idea of flexi-time and time off for parents and a third of all female directors chipped in that mothers were less productive.

"Many working mothers think other women are their harshest critics," says Jane Bruton. "For all the steps forward that have been taken over the last few decades, this toxic sisterhood is souring the workplace for women. Many resent what they see as special treatment of working mothers and worry that employment rights might actually put companies off employing women.

"It's a depressing picture because if we don't want to exclude a whole generation of women from the workplace, we need to work with each other, not against each other."