Image source, Getty ImagesImage caption, Steve Bannon has not publicly commented on Tuesday's vote in the House Select Committee

The US House of Representatives has voted to hold ex-Trump adviser Steve Bannon in contempt of Congress, opening him up to a potential prosecution.

Mr Bannon had defied a summons from a congressional panel investigating the 6 January riot at the US Capitol.

The House select committee voted to hold him in contempt on Tuesday, before passing the matter to the full chamber.

Thursday's vote largely fell along party lines, with 229 voting in favour compared to 202 against the move.

Only nine Republicans in the Democratic-controlled chamber voted to hold Mr Bannon in contempt.

House Speaker Nancy Pelosi is now expected to certify the vote before it is referred to the US Department of Justice, which has the final say on charges.

Media caption, When a mob stormed the US capitol

A committee investigating the riot has been chasing testimony from Mr Bannon about his communications with Mr Trump before the invasion of the Capitol, as well as any knowledge he may have had of plans to overturn the results of the November 2020 election.

Supporters of Mr Trump stormed the Capitol building and disrupted certification of President Joe Biden's electoral victory. More than 670 people have been arrested.

As Thursday's vote began, Representative Bennie Thompson, the chairman of the 6 January committee, said Mr Bannon is believed to have "valuable" information about the riot.

"He was deeply involved in the so-called Stop the Steal campaign," said the Mississippi Democrat.

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"He was reportedly in a 'war room' meeting the day before the riot and had been pressuring the former president to try to stop the counting of electoral college ballots.

"He himself warned that all hell would break lose on January 6."

Mr Thompson added that the committee believes it is important to make is clear that nobody can avoid a congressional subpoena.

"What sort of precedent would it set for the House of Representatives if we allow a witness to ignore us flat out without facing any kind of consequences?" he said.

US Attorney General Merrick Garland, who leads the justice department, testified earlier on Thursday to Congress about the likelihood of criminal charges for Mr Bannon.

Mr Garland said that the department will "apply the facts and the law and make a decision, consistent with the principles of prosecution".

Contempt of Congress cases are notoriously difficult to litigate – the last time such a prosecution took place was in 1983 against a Reagan administration official.

Mr Trump has urged former aides and allies to reject requests to testify before the 6 January committee, claiming that his communications from the time are protected by executive privilege – a legal principle that shields many White House communications.

Mr Bannon has yet to comment on the proceedings. His attorney has previously said that he will only co-operate if Mr Trump's executive privilege claim is legally resolved.