GRAND RAPIDS, Mich. (AP) — The trial for four men accused of plotting to kidnap Michigan Gov. Gretchen Whitmer that was scheduled to resume Monday has been postponed at least until Thursday because an essential participant tested positive for COVID-19.

U.S. District Judge Robert Jonker ordered the delay Sunday. Undercover FBI agents and informants were expected to testify in the coming weeks, as were two co-conspirators who pleaded guilty prior to trial as prosecutors build their case against four defendants accused of plotting to kidnap Whitmer.

READ MORE: Michigan Announces $1.5 Million Tuition Giveaway, 100 Children To Receive $15,000

The trial could last more than a month.

In testimony last week, prosecutors sought to counter defense claims that the four were entrapped, tricked by the FBI into joining a kidnapping conspiracy that wouldn’t have occurred to them otherwise. Prosecutors laid the groundwork of their case by calling FBI investigators to explain how they obtained covert recordings and social media posts. They entered some of that key evidence.

On Thursday, jurors heard for the first time a recording of one of the defendants specifically talk about kidnapping the Democratic governor. Barry Croft Jr. could be heard saying there should be “a quick, precise grab” of Whitmer.

READ MORE: AAA Offers 'Tow To Go' Program During Memorial Day Weekend

Jurors heard him and defendant Adam Fox in social media postings and recordings ranting about purported government abuses and saying violence was a valid response. Prosecutors say Croft and Fox were plot ringleaders.

Prosecutors said authorities arrested Fox, Croft, Daniel Harris and Brandon Caserta in October 2020 to thwart the kidnapping and to ensure the men couldn’t follow through on bids to buy powerful explosives.

In 2020, Whitmer was trading taunts with then-President Donald Trump over his administration’s response to COVID-19. Her critics regularly protested at the Michigan Capitol, clogging streets around the statehouse and legally carrying semi-automatic rifles into the building.

Whitmer, who is seeking reelection this year, rarely talks publicly about the case and isn’t expected to attend the trial. She has blamed Trump for stoking mistrust and fomenting anger over coronavirus restrictions and refusing to condemn hate groups and right-wing extremists like those charged in the plot. She has said he was also complicit in the deadly Jan. 6 Capitol insurrection.\

MORE NEWS: Holiday Travel And Gas: What To Expect At The Pump

© 2022 Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.