US prosecutors are seeking the stiffest punishments yet for participants in the deadly 6 January insurrection at the US Capitol by extremist supporters of Donald Trump, urging judges to make an example out of a man filmed punching a police officer and another who stormed the Senate chamber wearing a horned headdress.

At a court hearing on Wednesday, government lawyers will ask a judge to hand down a 44-month prison sentence for Scott Fairlamb, a former mixed martial arts fighter from New Jersey, who pleaded guilty in August to assaulting a police officer.

He was screaming at officers, in footage caught by their body-worn cameras, before shoving one and then punching him in the face.

He is to be sentenced by federal judge Royce Lamberth in Washington DC on Wednesday morning.

Separately, prosecutors in a late-night court filing recommended a four-year, three-month sentence for Jacob Chansley, the intruder at the Capitol attack who was seen around the world invading Congress, shirtless, wearing a horned headdress and furs, and heavily tattooed.

Chansley, of Phoenix, Arizona, was known to some at the time as the so-called “QAnon Shaman”.

He pleaded guilty in September to obstructing an official proceeding when he took part in the assault.

Lamberth, who is also handling Chansley’s case, will sentence him on 17 November.

In a court filing, Fairlamb’s defense lawyer asked the judge to “take into consideration the approximate 11 months the defendant has already served in custody” and not add additional time.

Attorney Harley Breite said his client had accepted responsibility for his actions.

Chansley’s attorney, Albert Watkins, said in a Tuesday court filing that Chansley should be released “as soon as possible”, noting that Chansley will have spent more than 10 months in pre-trial detention.

“I can say with confidence that Mr Chansley is in dire need of mental health treatment,” Watkins stated.

About 700 people have been arrested over the attack on the Capitol where Congress was meeting to certify Joe Biden’s November 2020 victory over Trump in the presidential election.

So far, about 120 people have pleaded guilty and two dozen have been sentenced. Most of the guilty pleas have involved non-violent misdemeanor offenses carrying short jail sentences or probationary sentences.