WASHINGTON (AP) — Supreme Court Justice Clarence Thomas on Monday temporarily blocked Sen. Lindsey Graham’s testimony to a special grand jury investigating whether then-President Donald Trump and others illegally tried to influence the 2020 election in the state.

Thomas’ order is intended to prevent Fani Willis, a Fulton County district attorney, from compelling Graham to testify while the Supreme Court weighs the senator’s request for a lengthier halt to the proceedings.

Willis has a deadline Thursday to tell the high court why Graham should have to answer the grand jury’s questions. Lower courts have ruled that his testimony can take place.

Thomas acted on his own, as the justice who handles emergency appeals from Georgia.

In the filing with the Supreme Court, attorneys for Graham, a top ally of Trump’s, sought to halt his possible testimony while he continues to appeal the order to appear before the special grand jury.

Graham’s office described the South Carolina Republican’s filing as an attempt “to defend the Constitution and the institutional interest of the Senate.” The lower court’s ruling, Graham’s office said would “significantly impact the ability of senators to gather information in connection with doing their job.”

The legal move was the latest in Graham’s ongoing fight to prevent his testimony in a case that has ensnared allies and associates of the former president. Some have already made their appearances before the special grand jury, including former New York mayor and Trump attorney Rudy Giuliani — who’s been told he could face criminal charges in the probe — attorneys John Eastman and Kenneth Chesebro, and former White House counsel Pat Cipollone.

Paperwork has been filed seeking testimony from others, including former White House chief of staff Mark Meadows, former national security adviser Michael Flynn, and former U.S. House Speaker Newt Gingrich.

Graham, a four-term senator who last won reelection in 2020, was first subpoenaed in July by Willis, who opened her investigation shortly after a recording of a January 2021 phone call between Trump and Georgia Secretary of State Brad Raffensperger was made public. In that call, Trump suggested Raffensperger could “find” the votes needed to overturn his narrow loss to Democrat Joe Biden.

Willis wants to question Graham about two phone calls he made to Raffensperger and his staff in the weeks after the election.

During those calls, Graham asked about “reexamining certain absentee ballots cast in Georgia in order to explore the possibility of a more favorable outcome for former President Donald Trump,” Willis wrote in a petition seeking to compel his testimony.

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