Employers in the private sector could be forced to reveal the differences in salary between male and female staff under the Equality Bill, published last week.
Harriet Harman, minister for women and equality and leader of the House of Commons, said it is hoped this will encourage employers to narrow the gender pay gap by making private sector employers publicly announce how the salaries of male and female staff compare.
Stephen Bevan, managing director of The Work Foundation, said: "We are not calling for everyone's pay to be published, but we strongly support the publication of pay structures and the conduct of mandatory 'equal pay audits' so that differences between the pay of men and women - especially when they are performing the same jobs at the same level - become clearer.
"We also advocate the inclusion of bonus payments in these audits because we have anecdotal evidence that some companies are using bonuses to reward men at a higher rate than women."
Harman outlined ways in which the private sector could shrink the gender pay gap. These include outlawing clauses prohibiting staff discussing their pay with colleagues, considering how public procurement could be used to deliver change, providing that an employment tribunal could make a recommendation applying not just to a successful complaint but to everyone in the workplace, creating a kite-mark on equality and having a commission to use its powers to investigate where most equality progress needs to be made.
Harman also announced measures to eliminate age and disability discrimination in the public sector and promote equality.
However, the bill has been regarded by some as positive discrimination, which is illegal.
Julie Quinn, partner at law firm Nabarro, said: "Positive discrimination under English law is, except in very limited circumstances, itself a discriminatory practice. Employers do not use quotas but we increasingly see businesses setting themselves 'targets' based on gender profile and ethnicity for the highest ranks within their organisation. Many fail to hit those targets [as] the rate is too slow. Ultimately, diversity makes business sense."