Trump attorney general once wrote unsolicited memo to Justice Department criticising Mueller probe

The memo says that there could be significant impacts should the Mueller probe find that the president obstructed justice

Former Attorney General William Barr has been nominated by Donald Trump to become the next attorney general, replacing Acting Attorney General Matthew Whittaker after the role was left open by Jeff Sessions. (AP)

The man who President Donald Trump wants to run the Department of Justice once wrote an unsolicited letter to the department expressing concerns about Special Counsel Robert Mueller's investigation into Russian meddling in the 2016 election.

William Barr wrote to the DoJ in June, criticising Mr Mueller for investigating whether Mr Trump obstructed justice during his interactions with former FBI director James Comey. Mr Comey had previously been in charge of the federal Russia probe.

The letter is likely to figure into Mr Barr’s Senate confirmation hearings, and could lead to questions on whether Mr Barr is capable of overseeing the investigation - one of his jobs as the head of the DoJ - in an unbiased manner.

In the memo, Mr Barr argues that there could be disastrous consequences if the special counsel’s office concludes that the president’s actions constitute obstruction of justice. Mr Barr contends in the memo that Mr Trump is legally permitted to do what he has done, and that he should not therefore be punished. The memo was first reported on by The Wall Street Journal.

In response to the memo, Senate Minority Leader Chuck Schemer said on Thursday that the White House should reconsider Mr Barr as a nominee for attorney general.

“Since Mr Barr hasn’t been formally nominated yet, the president must immediately reconsider and find another nominee who is free of conflicts and will carry out the duties of the office impartially”, Mr Schumer said.

Mr Trump announced Mr Barr was his pick for attorney general after he forced Jeff Sessions from the job. The president had frequently criticised Mr Sessions for his decision to recuse himself from oversight of the Russia investigation over his own meetings with Moscow officials.

Mr Sessions had recused himself in adherence to Justice Department policy, which stipulates that individuals involved in campaigns under investigation should not have oversight of those investigations.

Mr Barr has previously defended the president’s decision to fire former Mr Comey in a Washington Post opinion piece, writing that “Comey’s removal simply has no relevance to the integrity of the Russian investigation as it moves ahead”.

Mr Mueller was appointed as special counsel soon after that firing.