According to the Fawcett Society, 85% of British people would support mandatory pay audits, where employers would be required by law to check they are paying male and female staff fairly.
Fewer than half of men (48%) and fewer than a third of women (32%) think men and women receive the same amount of pay for doing jobs of equal value. And when told women are paid 23% less than men on average for doing jobs of equal value, 94% of the population think this needs to be addressed and eliminated.
The news comes as the Fawcett Society, Unison and the National Union of Students took a giant pay cheque to Gordon Brown on Friday. The date symbolises women's last pay cheque for 2009.
Ceri Goddard, chief executive of the Fawcett Society, said: "Last Friday women will effectively receive their last pay cheque of the year. As a result of the 17.1% full-time gender pay gap, 30 October marks the point in the year after which women across Britain can be said to be working for free.
"We cannot afford to let this continue. Government must face the fact the equal pay law isn't working. With one in three employment discrimination claims being for unequal pay, and cases taking up to 10 years to complete, the tribunal system is at breaking point. On top of that, last year the gender pay gap even got wider."
And TUC general secretary Brendan Barber added: "The Equal Pay Act is nearly 40 years old and yet women are still earning 17.1% less than men - the equivalent of 62 days unpaid work a year.
"The forthcoming Equality Bill represents a huge opportunity to put right the wrongs of the past 40 years. Women have waited long enough.
"But only by taking decisive action, some of which will cause discomfort among employers who are far too much at ease with women being underpaid, can the Government hope to end the gender pay gap."