A congressional committee investigating the January 6 insurrection at the US Capitol in Washington DC has voted unanimously to hold former White House aide Steve Bannon in contempt after he defied the panel’s subpoena.

The longtime ally of former president Donald Trump defied a subpoena for documents and testimony.

Mr Trump is still defending his supporters who broke into the Capitol that day.

He has aggressively tried to block the committee’s work by directing Mr Bannon not to answer questions while also suing the panel to try to prevent Congress from obtaining former White House documents.

The committee’s chairman, Democrat Bennie Thompson, said on Tuesday Mr Bannon “stands alone in his complete defiance of our subpoena” and the panel will not take no for an answer.

He said that while Mr Bannon may be “willing to be a martyr to the disgraceful cause of whitewashing what happened on January 6th — of demonstrating his complete loyalty to the former president”, the contempt vote is a warning to other witnesses.

Mr Thompson added: “We won’t be deterred. We won’t be distracted. And we won’t be delayed.”