Conservative lawyer John Eastman, who promoted a plan to keep Donald Trump in power, turned himself in to Georgia authorities on Tuesday.

The conservative is involved in a case of alleged conspiracy to annul the electoral defeat of the former US president in 2020.

Eastman turned himself in at a Fulton County jail and was arraigned and released a short time later.

It should be remembered that the lawyer was indicted last week alongside Trump and 17 other people, accused by district attorney Fani Willis of conspiring to subvert the will of Georgia voters in a desperate attempt to keep Joe Biden out of the White House. It was the fourth criminal case brought against the former Republican president.

Trump, whose bail was set at 200,000 dollars on Monday, said he will turn himself in to Fulton County authorities on Thursday.

His bail conditions prohibit him from intimidating co-defendants, witnesses or victims in the case, including on social media. He has a history of attacking the prosecutors leading the cases against him, including Willis.

Eastman said, in a statement provided by his lawyers, that he was turning himself in today (yesterday) after "an indictment that should never have been filed".

He also criticized the prosecution for targeting "lawyers and their zealous advocacy on behalf of their clients," and said that each of the 19 defendants had the right to rely on legal counsel and previous legal precedents to challenge the election results.

A former dean of Chapman University Law School in southern California, Eastman was a close adviser to Trump at the time of the January 6, 2021 attack on the US Capitol by the tycoon's supporters, who were trying to prevent the certification of Biden's electoral victory.

Eastman wrote a memo outlining the measures Vice President Mike Pence could take to stop the counting of electoral votes while presiding over the joint session of Congress on January 6, in order to keep Trump in office.

After the 2020 election, Eastman was among those who pushed to implement a list of "alternative" voters, falsely certifying that Trump won, and tried to pressure Pence into rejecting or delaying the counting of legitimate electoral votes for Democrat Joe Biden.

Bail bondsman Scott Hall, who was charged with participating in the tampering of election equipment in rural Coffee County, Georgia, also turned himself in today at the Fulton County Jail.

Two other defendants, former Justice Department lawyer Jeffrey Clark and former Georgia Republican Party chairman David Shafer, have filed papers seeking to transfer the case to a federal court.

Prosecutor Willis has already filed the case in Fulton County Superior Court, where the indictment was filed, proposing a trial date of March 4. Legal maneuvers, such as attempts to take the case to federal court, could delay the start of a trial.