Peter Navarro ordered to testify before federal grand jury on efforts to overturn Trump's election loss
White House trade adviser Peter Navarro. (Fox Business screengrab)

Peter Navarro has been subpoenaed to testify before a federal grand jury about his efforts to help Donald Trump overturn his election loss.

The former White House trade adviser said FBI agents served him the subpoena last week at his house seeking his testimony Thursday and any records he has related to the Jan. 6 insurrection, including "any communications" with the former president, reported the New York Times.

Navarro intends to file a lawsuit against the House select committee, along with House speaker Nancy Pelosi and Matthew Graves, the U.S. attorney for the District of Columbia, to block the subpoena, which he called the “fruit of the poisonous tree.”

The same grand jury has issued subpoenas to Trump attorneys Rudy Giuliani, Jenna Ellis, John Eastman and Kennth Chesebro seeking information about plans to create alternate slates of electors in states won by Joe Biden.

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Navarro plans to argue that only Trump can authorize him to testify, and his lawsuit will ask a judge to instruct the U.S. attorney to negotiate his appearance with the former president.