White House hopeful Sen. Kamala Harris (D-Calif.) is no longer being considered for the endorsement of a prominent progressive group after her campaign said she could not participate in a scheduled Q&A next month.

The labor union-backed Working Families Party (WFP) is conducting a series of live streamed sessions with six candidates ahead of a mid-September vote by its grassroots members and board to make an endorsement. WFP will be one of the first left-leaning groups to throw its support behind a 2020 candidate.

{mosads}“The one thing we asked of candidates who wanted to be considered by WFP members is that they had to be willing to take questions from us in a live Q&A. Our members were eager to ask Senator Harris about how she would address over-policing of communities of color, the existential threat of climate change, her position on healthcare, and how we can make our economy work for the many, not the few,” Nelini Stamp, director of strategy and partnerships at the Working Families Party, said in a statement to The Hill.

“We regret that Senator Harris did not agree to a time for an interview, and consequently is not moving forward in our process,” Stamp added.  

Sens. Bernie Sanders (I-Vt.), Elizabeth Warren (D-Mass.) and Cory Booker (D-N.J.); former Housing and Urban Development Secretary Julián Castro; and New York City Mayor Bill de Blasio are the five other candidates under consideration. They have all already completed Q&A sessions.

Harris’s campaign canceled her meeting with WFP two days ahead of the event, scheduled for Aug. 22, and told the group this week it would not be able to reschedule.

Harris spokesman Ian Sams confirmed to NBC News, which was the first to report the news, that “we weren’t able to make it work in time for their vote mid-September.” 

Harris’s campaign did not immediately respond to a request for comment from The Hill.

WFP, which works to elect “the next generation of progressive leaders,” endorsed Sanders in the 2016 presidential race.