A jury was selected Monday for the trial of former Donald Trump advisor Steve Bannon for defying a subpoena to testify before lawmakers investigating the attack on the US Capitol.

Bannon, who led Trump's successful 2016 presidential election campaign, was among dozens of people called by a congressional committee to testify about the 2021 storming of Congress by Trump supporters.

The 68-year-old refused the summons and was indicted on two charges of contempt of Congress.

A 22-person jury was selected on Monday to hear the case. The panel will be cut down to 12 jurors and two alternates on Tuesday, and opening arguments will begin in what is expected to be a speedy trial.

Bannon's lawyers sought to delay the start of the trial so it would not take place at the same time as the House committee's public hearings into the Capitol attack, but the judge refused the request last week.

Thousands of Trump supporters, many associated with ultra-nationalist and white supremacist groups, stormed the Capitol on January 6, 2021 in an effort to block the certification of Democrat Joe Biden's election victory.

They had been egged on by Trump in a fiery speech near the White House, during which he repeated his false claims of election fraud.

According to the House committee probing the riot, Bannon spoke to Trump the previous day.

Investigators believe Bannon and other Trump advisors could have information on links between the White House and the rioters.

After refusing to testify for months, Bannon finally agreed this month to cooperate with the House investigation, a move prosecutors said was a "last-ditch attempt to avoid accountability" by stalling his trial for contempt.

Judge Carl Nichols ruled the trial should go ahead anyway, saying, "I see no reason for extending this case any longer."

If convicted of contempt, Bannon faces a minimum sentence of 30 days and a maximum of one year in prison on each count.

He was Trump's strategy chief at the White House before being sacked in 2017.

Bannon was charged with conspiracy to commit wire fraud and money laundering after allegedly defrauding thousands of donors to a campaign to fund Trump's anti-migrant wall along the southern border.

In Trump's final hours in office, he pardoned Bannon.

More than 850 people have been arrested in connection with the attack on Congress. The assault left at least five people dead and 140 police officers injured.

Trump was impeached for a historic second time by the House after the riot -- he was charged with inciting an insurrection -- but was acquitted by the Senate.