Donald Trump plans to surrender to authorities in Georgia on Thursday -- the latest extraordinary step in a series of criminal indictments that will suck every ounce of oxygen from the first US Republican primary debate held just hours before.

The former president confirmed late Monday that he would turn himself in to the county jail in Atlanta the day after the debate in Milwaukee, ensuring a spectacle that could dash his rivals' hopes of profile-boosting coverage.

"Can you believe it? I'll be going to Atlanta, Georgia, on Thursday to be ARRESTED by a Radical Left District Attorney, Fani Willis, who is overseeing one of the greatest Murder and Violent Crime DISASTERS in American History," Trump posted on social media.

The runaway favorite for the Republican nomination is accused of leading a "criminal enterprise" to cling to power after his 2020 election defeat to Joe Biden, one of four criminal cases targeting him as he bids to return to the White House.

He and 18 co-defendants, all of whom were charged under Georgia's Racketeer Influenced Corrupt Organizations law, were given until Friday at noon (1600 GMT) to surrender.

The order bans Trump, who is out on a $200,000 bond, from intimidating co-defendants or witnesses, including on social media.

- Debate no-show -

The former president, long prized as a draw for a TV audience, had already announced on Sunday that he would be a no-show at the Republican presidential debates, despite entreaties from party leadership and Fox News executives.

His absence creates an opening for the chasing pack, who will attempt the high wire act of promoting themselves without angering Trump's base.

Florida governor Ron DeSantis will be center stage, flanked by fellow governor Doug Burgum, Senator Tim Scott of South Carolina, former vice president Mike Pence, businessman Vivek Ramaswamy and former governors Chris Christie, Nikki Haley and Asa Hutchinson.

But Trump will loom large over the event, with moderators Bret Baier and Martha MacCallum confirming they will ask the candidates about his indictments.

The 77-year-old billionaire's rivals have largely defended him -- or have at least avoided overt criticism -- over his mounting legal woes, echoing his complaints of being unfairly targeted by two-tier justice system.

The two-hour debate could make or break for DeSantis, who is languishing in a distant runner-up spot as his poll numbers slide.

His campaign says the governor will emphasize "his vision to beat Joe Biden, reverse American decline and revive the American Dream" rather than targeting other specific candidates.

- 'Legal baggage' -

"Everybody should debate. Everybody has a responsibility to earn people's votes. Nobody is entitled to anything in this world, least of all the Republican nomination for president," DeSantis told Fox News on Monday when asked about Trump.

Ramaswamy and Christie have indicated that they intend to go after DeSantis after his political action committee went public with advice urging him to attack them while defending Trump.

Trump's team is not entirely ceding the stage, however, and is planning a media blitz to make their presence felt on the ground.

Top aides will spin for Trump backstage and the Republican's pre-recorded interview by firebrand former Fox News host Tucker Carlson is expected to be posted on social media as the debate happens.

And Fox News is hoping the evening isn't entirely about Trump, and envisions questions on domestic and foreign policy.

"What people want is folks that are not afraid of Donald Trump and who's going to articulate a vision for a future and talk about the issues of the day that are impacting them, and not just focusing on Donald Trump's legal baggage," former congressman Will Hurd, a candidate who did not qualify, told MSNBC on Sunday.

The debate airs Wednesday at 8:00 pm (0100 GMT).