Hunter Biden, the scandal-plagued son of Joe Biden, is expected to plead guilty to two counts of wilful failure to pay federal income tax, the US justice department has said in a court filing. According to the plea deal, Hunter Biden will also enter a pre-trial diversion agreement on one offence of illegally possessing a gun while being a drug user. The justice department alleged that he possessed a Colt Cobra revolver in Delaware in October 2018 while “knowing that he was an unlawful user of and addicted to a controlled substance”. The agreement will allow the gun charge to be dropped if Hunter Biden meets certain conditions, which were not immediately clear Tuesday. The charges against Hunter Biden arose from an investigation by David Weiss, the US attorney in the president’s home state of Delaware, who was appointed by former president Donald Trump. Weiss is expected to recommend probation for the tax charges, and Hunter Biden will appear at an arraignment in the coming weeks. Weiss’ office indicated the investigation into Hunter Biden was “ongoing”, but lawyer Christopher Clark, who represents the president’s son, said the plea agreement would resolve the justice department’s inquiry. “I know Hunter believes it is important to take responsibility for these mistakes he made during a period of turmoil and addiction in his life,” Clark said in a statement. “He looks forward to continuing his recovery and moving forward.” The White House said in a statement: “The president and first lady love their son and support him as he continues to rebuild his life. We will have no further comment.” Hunter, 53, has long been the focus of attacks by Trump and his Republican allies who have accused him of wrongdoing in business dealings relating to Ukraine and China. Hunter has worked as a lobbyist, lawyer, investment banker and artist, and has publicly detailed his struggles with substance abuse. Hunter has had an increasingly public role at his father’s side, appearing at a state dinner honoring the French president, Emmanuel Macron; at the Kennedy Center Honors in Washington; and on a trip to the Republic of Ireland. The plea deal is likely to spare him prison time but it was immediately seized upon by Republicans in an effort to inflict political damage on the US president, who has announced his bid for re-election in 2024. Trump, who was indicted last week over allegations that he intentionally withheld classified documents from federal authorities, attacked the plea agreement as an injustice. “The corrupt Biden DOJ just cleared up hundreds of years of criminal liability by giving Hunter Biden a mere ‘traffic ticket’,” Trump said on his social media platform Truth Social. “Our system is BROKEN!” Congressman James Comer, the Republican chair of the House oversight committee, insisted the agreement would not prevent his panel from continuing to investigate Biden and his business dealings. “Let’s be clear: the Department of Justice’s charges against President Biden’s son Hunter reveal a two-tiered system of justice,” Comer said. “These charges against Hunter Biden and sweetheart plea deal have no impact on the oversight committee’s investigation. We will not rest until the full extent of President Biden’s involvement in the family’s schemes are revealed.” But a number of legal experts rejected Republicans’ claims of political bias, instead arguing that Hunter Biden’s plea agreement represented a rather harsh punishment considering the charges involved. “[F]irst time tax offenders like this rarely get prosecuted and even rarer to get jail time,” said Andrew Weissman, a 20-year justice department verteran who served under former special counsel Robert Mueller. “And false gun applications sadly also almost never get prosecuted or jail time. So this is if anything harsh, not lenient.” Hunter’s taxes and foreign business dealings have been under investigation by a federal grand jury in Delaware since at least 2018. His membership on the board of a Ukrainian energy company and his efforts to strike deals in China have raised questions by Republicans about whether he traded on his father’s public service. As the FBI sought to interview him in 2020, Hunter was forced to publicly acknowledge that he was under scrutiny, stating: “I take this matter very seriously but I am confident that a professional and objective review of these matters will demonstrate that I handled my affairs legally and appropriately, including with the benefit of professional tax advisers.” Democrats appeared to greet news of the plea agreement with a sigh of relief, eager to put the matter to rest as they turn their attention to the 2024 elections. “A five-year-long thorough investigation by a Trump-appointed US attorney has reportedly concluded with Hunter Biden pleading guilty to two misdemeanor tax charges and entering pretrial diversion on a gun-related charge,” said Senator Chris Coons, a Democrat of Delaware. “From press accounts, I am encouraged that Hunter is taking responsibility for his actions, paying the taxes that he owes, and preparing to move on with his life.”