Women's pay is growing at a slightly higher rate than men's but it would still take 187 years to close the gap, according to figures from the Chartered Management Institute (CMI) and CELRE.

The survey found that women's pay increased by an average of 6.8% over the past 12 months - a rise from 5.2% the previous year - compared to a rate of 6.6% for men.

But the average female executive takes home £13,655 less than a male counterpart doing the same job, the survey showed, and female directors would have to wait longest before achieving equal pay.

"At least with a glass ceiling it is possible to see through to the next level," said Jo Causon, director of marketing and corporate affairs at CMI. "However, when it comes to equal pay, it seems that the glass is now opaque.

"To have to wait several generations is inexcusable and it is time that the lip service of the three decades since sex discrimination was first outlawed is transformed into action."