United States President Donald Trump has granted clemency to everyone charged over the January 6, 2021 attack on the US Capitol in one of his first official acts in the Oval Office.

In a sweeping reversal of the years-long drive to punish those responsible for trying to overturn the outcome of the 2020 US election, Trump on Monday pardoned about 1,500 of his supporters and commuted the sentences of 14 others.

“This proclamation ends a grave national injustice that has been perpetrated upon the American people over the last four years and begins a process of national reconciliation,” Trump said in a proclamation posted on the White House website.

Trump’s pardons wiped the slate clean for many of those convicted of committing the most serious crimes on January 6, including Enrique Tarrio, the former leader of the far-right Proud Boys, who was sentenced to 22 years in prison for seditious conspiracy.

The pardons also erased the criminal records of more than 700 people convicted of misdemeanour offences, such as trespassing, and put a halt to hundreds of pending prosecutions.

Among the most high-profile figures to have their sentences commuted was Stewart Rhodes, the leader of the far-right Oath Keepers, who was sentenced to 18 years in prison for seditious conspiracy, obstruction of an official proceeding and tampering with documents and proceedings.

Asked if those who assaulted police should be punished, Trump said they had been in prison for a “long time already”.

“I see murderers in this country get two years, one year and maybe no time. So they’ve already been in jail for a long time. These people have been destroyed,” Trump said, describing their treatment as “outrageous”.

While Trump pledged to pardon many of the January 6 defendants during his re-election campaign, it had been unclear how far he would go to extend clemency to those who participated in the attack.

In an interview with Fox News last week, Vice President JD Vance said only those who had protested “peacefully” on January 6 should receive pardons.

“If you committed violence on that day, obviously you shouldn’t be pardoned,” Vance said. “And there’s a little bit of a grey area there.”

Trump’s act of clemency drew swift condemnation from Democrats and other critics of the president.

“The President’s actions are an outrageous insult to our justice system and the heroes who suffered physical scars and emotional trauma as they protected the Capitol, the Congress and the Constitution,” former Democratic House of Representatives Speaker Nancy Pelosi said in a post on X.

“It is shameful that the President has decided to make one of his top priorities the abandonment and betrayal of police officers who put their lives on the line to stop an attempt to subvert the peaceful transfer of power.”

A total of 1,583 people were charged over the events of January 6, when a mob of Trump supporters attempted to block a joint session of the US Congress from certifying US President Joe Biden’s election victory.

Rioters injured more than 140 police officers and inflicted economic losses of about $2.8m, according to US prosecutors.

More than 1,200 people were convicted of offences, including about 250 people convicted of assault.

Of the total, more than 700 people were sentenced to prison time.

Trump himself had faced charges over his role in the January 6 riot until the US Justice Department in November dismissed the case in line with its longstanding policy of not prosecuting a sitting president.