Michelle Obama almost abandoned her speech at a private fundraiser after being heckled by a gay rights activist.

The First Lady was addressing 200 Democratic party loyalists at the private event in Washington DC when she was interrupted by a female protester demanding White House action on gay and lesbian rights.

Ellen Sturtz, an activist with GetEqual, insisted that President Barack Obama sign an executive order banning anti-gay discrimination by federal contractors.

The president's wife left the lectern, approached Sturz and reportedly said: "Listen to me or you can take the mic but I'm leaving. You all decide. You have one choice."

Backed by encouragement from the crowd, Obama returned to the stage and Sturtz was escorted off the premises by security.

As 56-year-old Sturtz was accompanied out, she was allegedly heard describing herself as a "lesbian looking for federal equality before I die".

She told the Huffington Post: "I was asked by the First Lady to be quiet and I can't be quiet any longer.

"I was surprised by how negative the crowd seemed to be. It was a little unsettling and disturbing."

"She obviously thought she was going to make an example of me or something. I wasn't scared at all."