WASHINGTON (AP) — A nonpartisan congressional watchdog's finding that the two top officials at the Department of Homeland Security are legally ineligible to hold their posts is "erroneous" and should be withdrawn, a Trump administration official said Monday.

Acting DHS general counsel Chad Mizelle defended the legality of the administration's appointments and said the timing and the author of the finding by the General Accountability Office appear to be politically motivated.

"The GAO should rescind its erroneous report immediately," Mizelle wrote in a letter to the general counsel of the congressional watchdog agency.

GAO said in the finding released Friday that the appointment of acting DHS Secretary Chad Wolf and acting Deputy Ken Cuccinelli violate a federal law that regulates the appointment of senior government officials.

It is an important issue because there are pending lawsuits challenging DHS actions related to immigration and law enforcement that argue in part that Trump administration policies are invalid because the top officials are not legally eligible to hold those positions.

Mizelle, in addition to arguing that the GAO finding is legally flawed, questioned the timing of its release about 80 days before the November election and noted that the principal author had previously worked on a Democratic campaign and policy committee.

"As the reader reaches the report's conclusion, he is left with the sinking and inescapable feeling that something is afoot in the swamp," he wrote in a letter released by DHS.

The GAO report comes at a time of intense scrutiny of DHS over Trump administration immigration policies and the July deployment of federal agents in tactical gear to confront protesters outside federal buildings in Portland, Oregon.

It also comes as Miles Taylor, who served as DHS chief of staff from 2017-19, has endorsed former Vice President Joe Biden in the presidential race. He accused President Donald Trump of using DHS for "political benefit" by focusing on issues that would help his campaign at the expense of more pressing matters.

"After serving for more than two years in the Department of Homeland Security's leadership during the Trump administration, I can attest that the country is less secure as a direct result of the president's actions," Taylor wrote in an opinion piece in The Washington Post.

Taylor served under Secretary Kirstjen Nielsen, who signed an order of succession at DHS that is at the heart of the dispute over whether the appointments of Wolf and Cuccinelli are valid.

GAO determined that Nielsen was improperly replaced by Kevin McAleenan and, therefore, the later appointments of Wolf and Cuccinelli were invalid.

Mizelle counters in his letter that the succession was later clarified by Nielsen in an internal memo and when she swore in McAleenan as her replacement.

Ultimately, the issue is likely to be resolved by a court hearing one of the challenges to DHS policy and its leadership, said Stephen Vladeck, a professor at the University of Texas School of Law who has studied federal vacancy law and believes the appointments are invalid.

The Trump administration should act quickly to replace the officials, Vladeck warned. "Every day they leave Wolf in office they are increasing the risk that his appointment gets struck down and a whole bunch of polices get struck down with it," he said.