WASHINGTON (Reuters) - The U.S. Supreme Court on Monday rebuffed a challenge by three conservation groups to the authority of President Donald Trump’s administration to build a wall along the U.S.-Mexico border, a victory for Trump who has made the wall a centerpiece of his hardline immigration policies.

U.S. President Donald Trump attends a meeting with German Chancellor Angela Merkel during the G20 leaders summit in Buenos Aires, Argentina December 1, 2018. REUTERS/Luisa Gonzalez

The justices’ declined to hear the groups’ appeal of a ruling by a federal judge in California rejecting their claims that the administration had pursued border wall projects without complying with applicable environmental laws. The groups are the Center for Biological Diversity, the Animal Legal Defense Fund and Defenders of Wildlife.

Their lawsuits said construction operations would harm plants, rare wildlife habitats, threatened coastal birds like the snowy plover and California gnatcatcher, and other species such as fairy shrimp and the Quino checkerspot butterfly.

Brian Segee, an attorney at the Center for Biological Diversity, said he was disappointed that the court would not hear the case.

“Trump has abused his power to wreak havoc along the border to score political points,” Segee said. “He’s illegally sweeping aside bedrock environmental and public-health laws. We’ll continue to fight Trump’s dangerous wall in the courts and in Congress.”

Trump has clashed with U.S. lawmakers, particularly Democrats, over his plans for an extensive and costly border wall that he has called necessary to combat illegal immigration and drug smuggling. Congress, controlled by the president’s fellow Republicans, has not yet provided him the amount of money he wants.

The president has threatened a government shutdown unless lawmakers provide $5 billion in funding.

On Saturday, Trump said congressional leaders sought a two-week extension of funding ahead of a Dec. 7 deadline to fully fund the U.S. government and that he would probably agree to it.

Mexico has rejected Trump’s demand that it pay for the wall.

Illegal immigration was a central theme of Trump’s presidential bid, and he repeatedly invoked the issue ahead of the Nov. 6 congressional elections as a caravan of migrants from Central America made their way toward the United States. Trump deployed 5,800 U.S. troops to the border.

The three conservation groups sued last year in San Diego after the Department of Homeland Security authorized projects to replace existing border fencing at two sites in southern California, as well as the construction of prototype border walls.

The dispute centers on a 1996 law aimed at countering illegal immigration that gave the federal government the authority to build border barriers and preempt legal requirements such as environmental rules. That law also limited the kinds of legal challenges that could be mounted.

The groups argued that Trump’s wall projects did not fall under that law, and that the measure was unconstitutional because it gave too much power to unelected Cabinet officials to avoid laws such as the Endangered Species Act and the National Environmental Policy Act.

U.S. District Judge Gonzalo Curiel in February ruled that the administration had not exceeded its powers. The groups appealed the judge’s decision to the Supreme Court.

The groups have said that giving the federal government unfettered power to waive applicable laws and limit judicial oversight is ripe for abuse. With such power, the plaintiffs argued, officials could theoretically give contracts to political cronies to build walls with no safety standards using child migrant labor, and “kill bald eagles in the process.”

The Trump administration urged the justices not to take up the appeal. A spokeswoman for the Justice Department on Monday declined to comment.

Trump criticized Curiel in 2016 in a different case, a lawsuit accusing his now-defunct Trump University of fraud. Trump, while running for president, accused Curiel of being biased against him because of the Indiana-born judge’s Mexican heritage.