The pay gap between men and women has hardly closed in recent years, according to the latest findings.

Trade secretary Patricia Hewitt described the Equal Opportunities Commission's report as a "depressing snapshot" of British industry.

Hewitt said that "workplaces are still stacked against women fulfilling their true earning potential".

The research shows a key part of the problem is secrecy about pay rates which is helping to maintain the gap between the salaries of men and women.

More than a fifth of employers do not allow workers to share information about pay with their colleagues.

Most firms have no plans to check if they are paying women fairly, and more than one in five employers do not allow their staff to share information about pay rates, the commission found.

The EOC said the secrecy was helping to maintain the 19 per cent gap between the pay of men and women.

Women who work part-time earn 41 per cent less per hour than men who work full-time - the same gap as 25 years ago.

The group urged companies to check pay systems to make sure there was no bias against women.

The call is in line with a recommendation from an EOC taskforce two years ago, which was backed by the government.

EOC chairwoman Julie Mellor said the level of complacency and secrecy uncovered by the research was "staggering".

She said that employers have a "crucial role to play in tackling unequal pay".

"Employers now have no excuse for inaction. Although some have accepted that responsibility willingly, many others still don't seem to have got the message," she said on Monday.

Pay was still a "taboo subject" in many organisations, Mellor said.

Hewitt described the research as a "depressing snapshot that shows too many workplaces are still stacked against women fulfilling their true earning potential".

"Businesses should not be afraid of pay audits, because treating, and paying, men and women equally can only improve a company's performance in the long run," she added.

Hewitt, who is also the minister for women, said the research made her more determined to work with employers, unions and the EOC to close the pay gap.

"It is encouraging that over a third of large companies will have done a pay review by the end of the year," she said.

"However, together with the EOC, we will continue to monitor the take up of pay reviews to see what can be done to increase numbers."