Women will not outnumber men in the boardroom until 2081, if current levels of representation continue.

The prediction comes as the Equality and Human Rights Commission finds fewer women hold top jobs now than in 2006.

There are fewer women than men in 12 out of 25 categories it measured. In Westminster women comprise 19.3% of MPs, down from 19.5% in 2006.

While female representation among FTSE 100 directors has improved from 10.4% in 2006 to 11% this year, the commission estimates 5,700 women would need to rise through the ranks now to make any impact among Britain's 31,000 positions of power.

Nicola Brewer, chief executive of the Equality and Human Rights Commission, said: "We always speak of a glass ceiling. In some cases it appears to be made of reinforced concrete. We need radical change to support those who are doing great work. We need to help those who want to work better and release talent."