The effort to target Comey has been viewed with scepticism in the Eastern District of Virginia, the US attorney's office handling the case. The district's top federal prosecutor, Erik Siebert, resigned last week after drawing Trump's wrath for expressing doubts about the strength of the case, and the No 2 official, Mary "Maggie" Cleary, has also expressed concerns, according to people familiar with the situation.Some other prosecutors in the office have told Siebert's successor, Lindsey Halligan, that charges should not be filed due to lack of evidence, according to one of the sources.Halligan most recently served as a White House adviser, and before that was one of Trump's personal defence lawyers.Trump and Comey have had an acrimonious relationship since the start of the president's first term in 2017. Trump fired him as FBI director days after Comey publicly confirmed that the president was under investigation over his election campaign's connections to Russia. Comey then emerged as a prominent critic of the president, calling him "morally unfit" for office.Comey's firing led to the appointment of another former FBI chief, Robert Mueller, as a special counsel to take charge of the Russia probe, which unearthed numerous contacts between the campaign and Russian officials but concluded that there was not enough evidence to establish a criminal conspiracy.Trump repeatedly attacked the investigation as a "witch hunt," and his second administration has sought to undermine conclusions by US intelligence and law enforcement agencies about Russian interference in the 2016 presidential election, in which Trump defeated Democratic rival Hillary Clinton.A Justice Department internal watchdog found evidence of numerous errors but no political bias concerning the FBI's opening of the investigation. Republicans have long claimed that the investigation was intended to undermine Trump's first administration.The Justice Department's internal watchdog, in a 2019 report, faulted Comey for asking a friend to give memos detailing Comey's one-on-one interactions with Trump to the New York Times. The Justice Department during Trump's first term declined to pursue criminal charges against Comey.