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El Paso, Texas — Advocates for migrants filed a lawsuit late Thursday in federal court challenging a new Biden administration restriction on asylum that officials say will deter unlawful crossings along the U.S.-Mexico border.

The American Civil Liberties Union and other groups asked the federal district court in San Francisco to block the rule, saying the policy, which took effect Friday, violates U.S. asylum law.

At the center of the suit is a regulation the Biden administration is hoping will deter illegal border crossings following the end of the Title 42 pandemic-era expulsion policy. It expired at midnight Thursday due to the termination of the national COVID-19 public health emergency.

The policy, which mirrors Trump-era rules, disqualifies migrants who cross the southern border without permission from getting asylum if they did not first ask for humanitarian refuge in a third country, such as Mexico, on their way to the U.S.

Paula, foreground, of Guatemala, holds her daughter as she asks U.S. Customs and Border Protection officials about new asylum rules at the San Ysidro Port of Entry on Thursday, May 11, 2023, in Tijuana, Mexico.

Gregory Bull / AP

In practice, the rule will disqualify most non-Mexican migrants from asylum. Those found ineligible for asylum under the rule could face swift deportation to their home country or Mexico and a five-year ban from re-entering the U.S. Those who attempt to re-enter the country illegally could face criminal charges, the Biden administration has warned.

In their lawsuit, advocates said the Biden administration regulation “attempts to resuscitate and combine the illegal features” of two Trump administration policies that were blocked in court. One of those rules disqualified migrants from asylum if they entered the U.S. in-between ports of entry, while the other barred migrants from asylum if they failed to seek protection in a third transit country.

The ACLU successfully challenged both Trump-era rules and persuaded judges to halt them.

“The Rule operates just as the Trump Administration’s prior asylum bans did: Asylum seekers subject to the Rule—all non-Mexicans—are categorically barred unless they satisfy one of the enumerated and limited conditions or exceptions,” the suit says.

Under U.S. asylum law, migrants on American soil are allowed to request protection, regardless of how they entered the country. Because the system is massively backlogged, migrants wait an average of years for a decision. The legal threshold for asylum is very high and many migrants don’t ultimately meet the eligibility criteria of proving that they fled persecution that stemmed from certain factors, such as their religion or politics.

It’s unclear whether federal courts will find the Biden administration’s regulation illegal. While the new restriction is based on penalizing migrants for entering the U.S. without permission and for not seeking asylum elsewhere, it is less restrictive than the near-total asylum bans enacted under former President Donald Trump.

The Biden administration’s asylum restriction, for example, does not apply to unaccompanied children or migrants who secure an appointment to enter the U.S. through a mobile app for asylum-seekers in Mexico or who are sponsored by U.S.-based individuals under a program for Cubans, Haitians, Nicaraguans and Venezuelans.

The rule also includes limited exemptions for migrants facing an “imminent and extreme threat” in Mexico, those with “acute” medical emergencies and victims of severe human trafficking.

The Biden administration has also argued that its approach to the asylum restrictions is different than the Trump administration’s efforts because it is pairing the measure with expanded channels for would-be migrants to fly or otherwise enter the U.S. legally

“This rule responds to the elevated encounters we are experiencing at the border and is critical to creating an orderly process to seek protection in the United States at a time when Congress refuses to reform our broken immigration laws or provide the necessary funds to hire sufficient asylum officers and immigration judges to process claims in a timely manner,” Department of Homeland Security spokesperson, Luis Miranda, said in a statement.

U.S. border officials have reported a record high in migrant apprehensions under President Biden, and the number of illegal crossings has spiked to unprecedented levels in recent days in the lead-up to the termination of Title 42.

During this week’s first three days, an average of 10,000 migrants were apprehended daily after crossing the U.S.-Mexico border unlawfully. The U.S. government estimated that roughly 60,000 migrants were waiting in northern Mexico for a chance to enter the U.S., according to Border Patrol Chief Raul Ortiz.