Mamamia founder Mia Freedman has "unequivocally apologised" to members of the LGBT community, after an attempt to start a hashtag movement for married women to show support for marriage equality backfired.

In a post on Tuesday headlined "Straight, married women want marriage equality too," Freedman shared a photo of herself pointing towards her ring and encouraged other married straight women to do the same, along with the hashtag #married4marriageequality. Freedman has since clarified that she came up with the concept after being approached by Australian Marriage Equality. 

The backlash was swift on social media, with critics on Twitter labelling it "tone-deaf" and "gloating about your ability to get married". 

Others, including LGBT comedian Jordan Raskopoulos, took the concept and ran with it. 

The Twitter storm prompted Mamamia to delete the original tweet and remove both the photo and any reference to the hashtag from Freedman's opinion piece. She also took to Twitter to defend herself and apologise for the insensitivity of the post, and any distraction it had caused.

"Marriage equality is a human rights issue & is supported by the vast vast majority of straight, married people," Freedman tweeted on Wednesday morning.

"If I inadvertently offended anyone by calling for legally married women to raise their voices in support of those who can't legally married [sic], I unequivocally apologise."

In a statement to Fairfax Media, Freedman confirmed that she came up with the concept after being approached by Australian Marriage Equality (AME). 

"AME came to us recently to ask how to build momentum with women and mothers at a critical time for the campaign," she explained.  

"Together with AME I thought a demonstration of support from married women under the hashtag #married4marriageequality would help send the message that there is a huge tide of support that exists across Australia for marriage equality.

"I'm sorry if the images attached to that message in any way offended or distracted from its purpose. But I'm not sorry for trying to help build support for marriage equality so that all Australians have the legal right to marry the person they love."

Tiernan Brady, director of AME's Equality Campaign, told Fairfax Media Freedman is "a phenomenal advocate" for LGBT equality.

"She is a wonderful advocate on behalf of the mothers of Australia who support marriage equality because they want the best for their children," he said.  

This most recent faux pas comes weeks after Freedman sparked an international media storm following "cruel and humiliating" comments she made about U.S. author Roxane Gay during a Mamamia podcast, for which she also apologised.