The national Black Lives Matter network has asked the Democratic National Committee to hold a presidential debate devoted exclusively to the topic of racial justice in America.

In a petition posted at Color of Change on Tuesday, the group told DNC Chair Rep. Debbie Wasserman-Schultz (D-FL) that black voters “deserve substantive responses and policy recommendations” from the Democratic field.

“It is not enough to poll the Presidential candidates on whether or not they think “Black Lives Matter” or “All Lives Matter,” the petition reads.

This question came up during the first of six DNC-approved Democratic debates, held in Las Vegas, Nevada on Oct. 13. Sen. Bernie Sanders (I-VT) and former Maryland Gov. Martin O’Malley affirmed that “black lives matter” to the only question during the over two-hour debate that specifically addressed the movement’s concerns.

Black Lives Matter activists argue that the limited number of debates allows candidates to pay scant attention to issues like poverty in the black community, mass incarceration, and racist policing. Other candidates, including Sanders and O’Malley, have asked the DNC to hold more debates in order to give Democrats more opportunities to air their views, as have two top members of the DNC staff.

The Republican National Convention will host 12 presidential debates during the 2016 election cycle.

“Limiting the number of debates unfairly privileges some candidates over others, and cheats voters out of the opportunity to fully engage candidates on issues we care about,” BLM activists wrote in the petition.

Several prominent candidates have developed a rocky relationship with Black Lives Matter on the campaign trail. In June, Sanders was forced offstage at his own rally by the co-founders of the Seattle chapter, who decried his “white supremacist liberalism.” O’Malley has been criticized for upholding “broken windows” policing during his tenure as Baltimore mayor—a policy that activists say resulted in the disproportionate imprisonment of minorities. And Democratic frontrunner Hillary Clinton has faced attacks for the crime control policies enforced by her husband Bill during his presidency.

As the activists put it in their petition, “This last year alone has demonstrated clearly that Black lives are under attack—from police violence to the murders of black trans women to economic disenfranchisement and neoliberal polices. It’s time to extend the public conversation beyond the status quo.”

As of 1:30 PM ET, the petition had garnered over 540 signatures.