Protesters are poised to flood streets in cities across the country on Saturday urging action to reunite the thousands of migrant families separated at the border due to a controversial Trump administration policy.

Galvanized by a federal judge's order this week that the government must act quickly to reunite children with their families, immigration and civil rights activists are set to take over Lafayette Square near the White House as they launch protests on Saturday.

The demonstration in downtown Washington, D.C., will mark the epicenter for the "Families Belong Together" march, which includes more than 700 sister protests planned in all 50 states, according to organizers.

ADVERTISEMENT

"We see the outrage and we see that this has to be taken right to the White House, right to Donald Trump to stop the family separations," Rep. Pramila Jayapal Pramila JayapalDHS opens probe into allegations at Georgia ICE facility Progressive Caucus co-chair: Whistleblower complaint raises questions about 'entire detention system' Buttigieg, former officials added to Biden's transition team MORE (D-Wash.) said last week on MSNBC.

Among the organizations backing the Saturday protests are the American Civil Liberties Union (ACLU), Amnesty International, the Anti-Defamation League and the Southern Poverty Law Center, among dozens of others. "Hamilton" creator Lin-Manuel Miranda is among those slated to speak at the rally.

The planned marches are the latest in a series of massive, nationwide protests against Trump administration's policies.

Few policies have elicited as much public furor as the administration's "zero tolerance" immigration policy, which calls for the prosecution of all people who illegally cross into the United States through its southern border.

That policy, announced by Attorney General Jeff Sessions Jefferson (Jeff) Beauregard SessionsGOP set to release controversial Biden report Trump's policies on refugees are as simple as ABCs Ocasio-Cortez, Velázquez call for convention to decide Puerto Rico status MORE in April, has led to thousands of migrant children being separated from their parents or guardians at the U.S.-Mexico border in a matter of weeks as the adults face prosecution.

Despite his insistence that Democrats were to blame for the separations and that his administration was merely enforcing the law, President Trump Donald John TrumpBiden on Trump's refusal to commit to peaceful transfer of power: 'What country are we in?' Romney: 'Unthinkable and unacceptable' to not commit to peaceful transition of power Two Louisville police officers shot amid Breonna Taylor grand jury protests MORE reversed course last week, signing an executive order allowing minors to be detained alongside their parents.

But that executive order raised questions about how the administration planned to enforce the measure. A 1997 consent decree prohibits the government from holding minors for more than 20 days — a limit that does not apply to adults. It also raised the question of what the government planned to do with the thousands of children who have already been separated from their families.

A federal judge in San Diego responded to a lawsuit over the issue this week, ordering the government to work swiftly to reunite migrant children with family members. Under that order, children under the age of 5 must rejoin their families within 14 days, while older children must be reunited within 30 days.

How the government will go about reunifying migrant families by the deadline remains unclear.

Lawmakers have also expressed a willingness to address the family separation issue with narrow legislation. But any measure will have to wait until after Congress's July Fourth holiday recess, which extends until July 10.

Lee Gelernt, a lawyer for the ACLU who argued the lawsuit in San Diego this week, said that the organization had seen some efforts to reunify families, but not a lot.

"We believe the administration can pull this off. When the United States government puts all its resources to work, it can something like this done easily," he told reporters on a conference call Wednesday.