Joe Biden has issued “a full and unconditional” pardon to son Hunter Biden covering his son’s convictions on federal gun and tax charges, the US president explained in a statement released by the White House on Sunday.

The decision marks a reversal for Biden, who has repeatedly said he would not use his executive authority to pardon his son or commute his sentence.

The pardon comes in advance of Hunter Biden’s 12 December sentencing for his conviction on federal gun charges. Hunter Biden also was scheduled to be sentenced in a separate criminal case four days later, after pleading guilty in September on federal tax evasion charges.

In the statement, Joe Biden argued that he had kept his word to “not interfere with the Justice Department’s decision-making, and I kept my word even as I have watched my son being selectively, and unfairly, prosecuted”.

Hunter Biden was found guilty in Delaware in June on three felony counts relating to his purchase of a handgun in 2018 because he wrote on his gun-purchase form, falsely, that he was not a user of illicit drugs.

But Joe Biden said on Sunday evening that his son had been prosecuted “without aggravating factors like use in a crime, multiple purchases, or buying a weapon as a straw purchaser, people are almost never brought to trial on felony charges solely for how they filled out a gun form”.

“It is clear that Hunter was treated differently,” Biden said, adding that the charges in the case “came about only after several of my political opponents in Congress instigated them to attack me and oppose my election”.

The pardon also covers Hunter Biden’s tax evasion conviction and all “offenses against the United States which he has committed or may have committed or taken part in during the period from January 1, 2014 through December 1, 2024, including but not limited to all offenses charged or prosecuted”.

But Joe Biden noted in the statement that “those who were late paying their taxes because of serious addictions, but paid them back subsequently with interest and penalties, are typically given non-criminal resolutions”.

Biden accused his political opponents of singling out his fifty-four year-old son.

“No reasonable person who looks at the facts of Hunter’s cases can reach any other conclusion than Hunter was singled out only because he is my son – and that is wrong,” he said

“There has been an effort to break Hunter – who has been five and a half years sober, even in the face of unrelenting attacks and selective prosecution. In trying to break Hunter, they’ve tried to break me – and there’s no reason to believe it will stop here. Enough is enough.”

Speculation had been mounting that the president would issue a pardon since Hunter was seen with his father in Nantucket over the Thanksgiving break.

Donald Trump floated the idea of pardoning Hunter Biden during a radio interview in October while his father was still then formally opposed to the idea.

“I wouldn’t take it off the books,” Trump said. “See, unlike Joe Biden, despite what they’ve done to me, where they’ve gone after me so viciously ... And Hunter’s a bad boy.”

A laptop that Hunter Biden had left in a Delaware repair shop, that made its way into Republican hands, formed a scandal in the closing days of the 2016 election. Republicans claimed that the so-called “laptop from hell”, which featured images of Hunter posing with guns, sex workers and crack cocaine, was suppressed by media favorable to Democrats.

Hunter Biden later published a book, Beautiful Things: a Memoir, that detailed some of his exploits as a drug addict. But the Biden family denied more serious accusations that Hunter’s profitable financial arrangements with businesspeople in Ukraine and China amounted to graft using the family name.

In the statement announcing the pardon, Joe Biden said that for his “entire career” he had followed a simple principle to tell the truth to the American people.

“Here’s the truth: I believe in the justice system, but as I have wrestled with this, I also believe raw politics has infected this process and it led to a miscarriage of justice – and once I made this decision this weekend, there was no sense in delaying it further. I hope Americans will understand why a father and a President would come to this decision.”