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The Trump administration wants to nix a legal challenge to a presidential order easing enforcement of an IRS rule that limited religious organizations' political activity.

The Justice Department on Tuesday asked a federal judge to dismiss a lawsuit filed in May by a Wisconsin-based atheist group. The Freedom From Religion Foundation argues President Donald Trump's order is unconstitutional because it grants preferential treatment to religious organizations while secular groups must still abide by the law.

At issue is a 1954 federal law that forbids groups such as churches from participating in political campaigns. Trump's order directs the Treasury Department not to take "adverse action" against churches or religious organizations for political speech, part of a promise to conservative Christians who supported his White House bid. He said at the time that he was giving churches their voices back.

The atheist group immediately sued, arguing the president lacked the power to overturn legitimate law.

In court filings, the Justice Department said the executive order does not alter existing law and called the group's claims baseless.

Trump's order "merely directs that the government not take adverse action against religious organizations that it would not take against other organizations in the enforcement of the restrictions," the Justice Department wrote.