Donald Trump has pardoned Michael Flynn, his first national security adviser who pleaded guilty to lying to the FBI about contacts with a Russian official. Trump announced the long-expected pardon in a tweet on Wednesday. “It is my Great Honor to announce that General Michael T Flynn has been granted a Full Pardon,” Trump wrote. “Congratulations to General Flynn and his wonderful family, I know you will now have a truly fantastic Thanksgiving.” Trump is expected to offer pardons to a number of key aides before he leaves office on 20 January. He has already commuted the sentence of Roger Stone, a longtime ally who like Flynn, campaign manager Paul Manafort and adviser George Papadopoulos was convicted under special counsel Robert Mueller’s investigation of Russian election interference and links between Trump and Moscow. Stone was sentenced to more than three years in prison, after being found guilty of obstruction, lying to Congress and witness intimidation. His conviction stands. Flynn had not been sentenced. Neither have Trump’s former campaign CEO and White House strategist Steve Bannon, charged with fraud, or his personal attorney Rudy Giuliani, reportedly under federal investigation for potential violations of lobbying law. While the pardon for Flynn was widely expected, its announcement prompted widespread criticism. Adam Schiff, the Democratic chair of the House intelligence committee, wrote on Twitter: “Donald Trump has repeatedly abused the pardon power to reward friends and protect those who covered up for him. This time he pardons Michael Flynn, who lied to hide his dealings with the Russians. It’s no surprise that Trump would go out as he came in – Crooked to the end.” Nancy Pelosi, the speaker of the House, called it “an act of grave corruption and a brazen abuse of power”. Noah Bookbinder, executive director of the nonprofit government watchdog Citizens for Responsibility and Ethics in Washington, or Crew, said the Flynn pardon “once again shows that to Donald Trump, ‘law and order’ does not apply to his wealthy white allies, it was merely a racist dog whistle meant to win him political support.” Flynn, a retired general, was a trusted Trump surrogate on the campaign trail in 2016. But he served just 24 days in the White House before Trump fired him for lying to Vice-President Mike Pence about a conversation in which he told Russian ambassador Sergey Kislyak Moscow should not respond to sanctions imposed by the Obama administration. As part of a deal with Mueller, Flynn pleaded guilty to lying to the FBI. He became a cause célèbre among Trump supporters, who claimed he was victimised by the Obama administration and entrapped by the bureau. Flynn’s fate became entangled with that of James Comey, the FBI director Trump fired in May 2017, triggering the appointment of Mueller. On Wednesday another former prosecutor, Mimi Rocah, now district attorney-elect for Westchester county, New York, tweeted that the road to Flynn’s pardon “started with Trump telling Comey, ‘I hope you can see your way clear to letting this go’ and Comey resisted that pressure”. In January this year Flynn sought to withdraw his guilty plea, prompting a drawn-out legal battle between the presiding judge and a Department of Justice led by William Barr, a close Trump ally. Trump repeatedly voiced his support, notwithstanding a frequently cited tweet from December 2017 in which he wrote: “I had to fire General Flynn because he lied to the Vice-President and the FBI. He has pled guilty to those lies. It is a shame because his actions during the transition were lawful. There was nothing to hide!” Flynn was represented by Sidney Powell, a lawyer recently ejected from Trump’s lawsuits challenging results in his election defeat by Joe Biden after she voiced wild conspiracy theories. In court in September, Powell said she had asked Trump not to pardon Flynn. On Wednesday, Rocah wrote: “Henchman Barr tried to do it and was stopped by judicial oversight. So, here we are. Corruption from beginning to end.” Trump has pardoned allies including the former New York police commissioner Bernard Kerik and former Arizona sheriff Joe Arpaio. Debate now swirls about whether the president will try to pardon himself – a move that would be historically unusual, and which if successful could only apply to federal issues and not cases at state level. In a statement on Wednesday, White House press secretary Kayleigh McEnany said Flynn “should never have been prosecuted [and] should not require a pardon” because “he is an innocent man”. In a statement, Flynn’s family said they were “grateful” to Trump for “answering our prayers, and the prayers of a nation, by removing the heavy burden of injustice off the shoulders of our brother Michael, with a full pardon of innocence”. In fact, as the Department of Justice points out, a presidential pardon still implies guilt. A pardon is “granted in recognition of the applicant’s acceptance of responsibility for the crime”, the DoJ says, “and established good conduct for a significant period of time after conviction or completion of sentence. “It does not signify innocence.”