The measure, put forward by Labour, will require companies which employ more than 250 staff to publish their own gender pay gap in their annual report.

Ms Osborne was joined in Parliament by Gwen Davis, Sheila Douglass, Vera Sime and Eileen Puller, four of the original Dagenham women who went on strike for equal pay leading to the Equal Pay Act of 1970, Stars of the hit musical Made in Dagenham also lent their support, including Gemma Arterton and Isla Blair.

Despite Labour voting through the motion this week, Liberal Democrat and Conservative MPs failed to vote in favour after the Government indicated that it did not intend to make pay transparency the law.

The campaign for pay transparency is being led by Labour in Parliament, and supported by Grazia magazine and employers, including PricewaterhouseCoopers and Genesis Housing, who are amongst just five companies known to voluntarily publish their pay gap.

"Shockingly women still earn an average 81p for every pound earned by men, despite the Equal Pay Act being passed 44 years ago. To coincide with the vote Labour is releasing new analysis of official figures which show that – because of the gender pay gap, women earn an average £209,976 less over their lifetime than men.," Ms Osborne said.

"Women and their families will be wondering why the Tories and Lib Dems failed to back equal pay for millions of women across Britain. Women shouldn’t have to wait another generation for equal pay.

"Pay transparency will shine a light on the problem and help employers to close the pay gap once and for all. This Government might not be prepared to act but a Labour Government will.'