The 43-year-old employment minister compared the "Leave" European Union (EU) campaign with the fight for the right of women to vote by the suffragettes in late 19th century England.
Speaking at the launch of pro-EU exit group 'Women for Britain' yesterday, she said:"In many ways, Women for Britain are fighting for exactly the same cause. The suffragettes fought for our democratic freedom. Now, we are the ones who must fight to protect it.
But Helen Pankhurst, great-granddaughter of suffragette leader Emmeline Pankhurst, hit back saying the comparison was "unacceptable".
She told the 'Guardian': "My great-grandmother fought tirelessly for women's rights and dedicated her life to making sure women could live their lives free from discrimination. It is unacceptable to use her achievements to argue for something that is so out of line with the spirit of international solidarity that defined the suffragette movement.
More From This Section
Both the "Remain" and "Leave" campaigns used International Women's Day yesterday to try to encourage female voters to engage in the EU referendum, amid some evidence that more women than men are undecided about which side to back.
Patel, also British Prime Minister David Cameron's Indian Diaspora Champion, argued that leaving the EU would "enhance our democracy and empower women" and attacked the Remain campaign's claims that women's rights would be at risk if the UK left the EU.
"A vote to leave would put all of this at risk, which is why I am proud to play my part in this video to help demonstrate to women across the UK how each one of us benefits from our seat at the top table," Morgan said.