Donald Trump’s nominee for attorney general will tell Senators at his confirmation hearing “it is vitally important” that Special Counsel Robert Mueller be allowed to complete his Russia investigation.

William Barr is scheduled to face questions from the Senate Judiciary Committee on Tuesday, which will include his views on the special counsel’s probe into Russian election medlling and potential coordination between Moscow and the president’s 2016 campaign.

Mr Barr will say he has known Mr Mueller for decades, respects him and believes he should be allowed to complete his work, according to the transcript.

Democrats have raised concerns about comments Mr Barr has made about the seemingly intensifying probe, including an unsolicited memo he sent the Justice Department last year criticising the special counsel’s inquiry into whether Mr Trump sought to obstruct justice.

A controversial choice to lead the Justice Department, Mr Barr appears to hold many of the same views as his predecessor in the role, former Attorney General Jeff Sessions, particularly when it comes to immigration.

Mr Barr will also tell senators he believes the department should continue to prioritise immigration enforcement and the government must be able to hold and remove people who illegally enter the US, the transcript revealed.

He will reportedly say the Justice Department cannot allow people to flout America’s legal system by “crashing in through the back door.”

His comments on the Russia investigation may come as a slight relief to Democrats, after Mr Trump has complained that his first attorney general, Jeff Sessions, did not protect him from the investigation. Legislatorshad demanded assurances that Mr Barr will be impartial and allow Mr Mueller’s investigation to continue.

The latest nominee will tell the Senators Tuesday that Mr Trump did not seek any assurances or promises over the investigation before nominating him, according to the transcript.

Mr Barr says the president “sought no assurances, promises, or commitments from me of any kind, either express or implied, and I have not given him any”, other than a promise to run the department with integrity.

Additional reporting by AP