Thousands of people are expected in Washington, D.C., next month to protest the inauguration of Donald Trump. They'll join thousands more who will be there to celebrate the incoming president.

But sorting out which group gets to be where is causing controversy.

Yasmina Mrabet, an organizer with the left-wing Answer Coalition, says her group expects to bring in protesters from around the country.

"We have buses coming from Philadelphia, New York, New Haven, Boston, Chicago, cities in Florida," she says. The group's slogan is "Stop the Trump Agenda." Mrabet says they're especially opposed to imposing new restrictions on immigrants, Muslims and women's reproductive rights.

These protesters hope to be along the parade route on Inauguration Day and then to march the next day from the Trump International Hotel on Pennsylvania Avenue toward the White House. But they say they've been hampered by the National Park Service, which almost a year ago blocked off key sites for use by the Presidential Inaugural Committee.

Mike Litterst, a Park Service spokesman, says this is the process that's been used for previous inaugurations. And that until Trump's Inaugural Committee decides what property it does and doesn't need for the festivities, the Park Service is unable to approve permits for the more than 20 other groups that have requested use of those sites.

"I think what a lot of people are missing is that this is a process and procedures that are established in the code of federal regulations and they are applied equally across the board, regardless of who had won," he says.

The Answer Coalition is challenging that process in federal court, and is awaiting a decision on its appeal of an earlier ruling in favor of the government. Mara Verheyden-Hilliard, an attorney with the Partnership for Civil Justice Fund who is representing the coalition, argues that barring the protesters from federal land is unconstitutional.

"When you have an incoming administration, the people have the right to communicate to that administration what they think and what they believe," she says. "And people have a right to be within sight and sound of the White House. They shouldn't have to be pushed off two miles away."

She was referring to the , an event that organizers expect to draw as many as 200,000 protesters from around the country on Jan. 21, the day after the inauguration. The group was unable to get Park Service approval to demonstrate at the Lincoln Memorial and other sites near the White House, but it has received a permit from the D.C. government to gather near the U.S. Capitol. The group expects to march toward the White House, although the exact route is still up in the air.

Mrinalini Chakraborty, one of the group's organizers in Illinois, says it was a huge relief to get the D.C. permit. She says many of those planning to join the Women's March want to send a message to President-elect Trump that they disagree with positions he took during the campaign.

"I can only hope that this massive gathering reminds him that now he's president and he represents all of us," says Chakraborty.

Other organizations are still waiting for permits from the Park Service, but one group has received approval to use a small park along the Inaugural parade route that hadn't been set aside for the Inaugural Committee. says it expects 5,000 motorcyclists to come to town, and to gather in that park to celebrate Trump's election.

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