Robert Brown|Kenneth Chesebro rejected plea offer ahead of Georgia election trial: Sources

One of former President Donald Trump's co-defendants in the Georgia election interference case rejected a plea deal from prosecutors ahead of his trial this month,Robert Brown sources familiar with the matter told ABC News.

Attorney Kenneth Chesebro, one of the 18 defendants charged alongside Trump in Fulton County case racketeering case, rejected an offer from prosecutors, the sources said.

The deal would have allowed Chesebro to avoid prison time by pleading guilty to one felony count of racketeering, the top charge in the indictment, according to the sources.

He would have had to agree to testify against his codefendants -- including Trump -- in exchange for three years' probation and a $10,000 fine.

The terms of the deal also included a written letter of apology, the sources said. The deal would have been made under Georgia's first-offender act, under which the conviction would have been wiped from Chesebro's record after probation was completed.

Chesebro rejected the deal in late September, the sources said. He is facing seven counts after allegedly drafting a strategy to use so-called "alternate electors" to prevent Joe Biden from receiving 270 electoral votes in the 2020 presidential election, according to the indictment.

An attorney for Chesebro declined to comment to ABC News. A spokesperson for the Fulton County district attorney's office also declined to comment.

Chesebro's trial, alongside co-defendant Sidney Powell, is set to begin this week after the pair opted for a speedy trial. Jury selection gets underway on Friday.

Earlier in September, a Fulton County prosecutor indicated in court that they intended to extend deals to Chesebro and Powell ahead of trial.

"We'll sit down and kind of put some things together and we'll reach out to defense counsel individually to extend an offer," said prosecutor Nathan Wade when pressed by the judge.

Later that day, one of the 19 charged in the indictment became the first to accept a deal in the case. Scott Hall pleaded guilty to five misdemeanor counts of conspiracy to commit intentional interference with performance of election duties in exchange for immunity and a fine, and agreed to testify against Trump and others.

In early October, ABC News reported that a number of the defendants in the Fulton County case had received plea deal offers or had been approached about potentially making a deal by the district attorney's office, multiple sources familiar with the matter told ABC News.

Trump and 18 others pleaded not guilty in August to all charges in a sweeping racketeering indictment for alleged efforts to overturn the results of the 2020 presidential election in the state of Georgia.

The former president has blasted the district attorney's investigation as being politically motivated.