About 100 young activists with the Sunrise Movement rallied outside the Democratic National Committee headquarters on Tuesday, demanding the party to reverse its ban on holding a climate change debate among the 2020 presidential candidates.

Activists have been calling for a full presidential debate dedicated to climate change as the issue has become a top priority for voters, pushing candidates to develop and release detailed policy proposals in the process. In addition to the protest in Washington, D.C., they’re calling on supporters to sign a petition demanding a climate debate.

“It’s an emergency, and we need our leaders to act like it,” said Abby Leedy, a protester from Philadelphia, outside the DNC headquarters a few blocks from the U.S. Capitol.

The DNC is not only refusing to hold a debate but threatening to bar any candidates who participate in a third-party climate debate on their own from future DNC debates. DNC Chair Tom Perez said in a Medium post earlier this month that the party would not hold any issue-specific debates because it could not allow individual candidates to dictate the terms of debate. His position came in response to Washington Gov. Jay Inslee, who has made climate change the centerpiece of his presidential campaign and has called for a climate-centric debate.

“If we change our guidelines at the request of one candidate who has made climate change their campaign’s signature issue, how do we say no to the numerous other requests we’ve had?” Perez wrote. “How do we say no to other candidates in the race who may request debates focused on an issue they’ve made central to their own campaigns?”

Sunrise activists rejected Perez’s framing of the issue. “When you say this is a single issue, we know that’s not true,” said Leedy. “We know that this affects every aspect of our lives.”

In May, the Sunrise Movement wrapped up its nationwide tour by calling for a mass mobilization to pressure Democratic contenders to center on climate change in the 2020 election and pledge to refuse contributions from the fossil fuel industry. So far, 18 candidates have signed the environmental group’s No Fossil Fuel Money pledge, including Inslee, Pete Buttigieg, and Sens. Bernie Sanders, Elizabeth Warren, Kamala Harris, and Cory Booker. Former Vice President Joe Biden is one of six candidates who have not yet signed.

Climate change has emerged as one of the top issues voters care about ahead of the 2020 election. A recent CNN poll found a majority of likely Iowa caucus participants consider climate change to be the greatest threat against humanity.