The Confederation of British Industry (CBI) said the Equal Pay Taskforce has come up with an "ineffective and disproportionate" proposal for closing the gender pay gap.
It said requiring employers to carry out regular pay audits would not have a significant impact but would impose an excessive administrative burden.
The CBI said there is no academic evidence clearly demonstrating that unfair discrimination by employers is the main cause of the pay gap.
It argued that the main causes are that more women work in low pay sectors and that women tend to have less work experience, largely because of family responsibilities.
The CBI added that the best way to change the situation is to remove the barriers to equality of opportunity between men and women in the workplace.
Solutions might include improving childcare facilities, promoting flexible working patterns, providing better quality careers advice and breaking down gender stereotypes.
Susan Anderson, Director of Human Resources Policy, said: "The pay gap is a problem but the taskforce is directing too much of its firepower at the wrong target. Statutory pay auditing would have little impact and would be a real burden. Gathering, analysing and understanding the data would be slow and complex. Many small firms would not have the resources or expertise.
"The causes of the pay gap are much more complex than just unfair discrimination. We need to give more choices to women who are trying to balance work with family responsibilities. Better childcare facilities would be one of the more productive ways of doing this. We also need to improve careers advice to encourage more women into higher paying jobs."