The US Justice Department expects to make a redacted version of special counsel Robert Mueller’s report on the Russia investigation public on Thursday morning, a spokeswoman has said.

The redacted report would be sent to Congress and also made available to the public, Kerri Kupec added.

As Washington counted down to the release, Donald Trump stepped up his attacks in an 11th-hour effort to undermine the report’s findings.

The president unleashed a series of tweets on Monday — including two just minutes after the Justice Department’s announcement — focusing on the favourable toplines in the previously released summary produced by attorney general William Barr.

Mr Mueller officially concluded his investigation late last month and submitted the confidential report to Mr Barr. Two days later, the attorney general sent Congress a four-page letter that detailed Mr Mueller’s “principal conclusions”.

In his letter, Mr Barr said the special counsel did not find a criminal conspiracy between Russia and Trump associates during the campaign, but Mr Mueller did not reach a definitive conclusion on whether Mr Trump obstructed justice.

Instead, the special counsel presented evidence on both sides of the obstruction question. Mr Barr said he did not believe the evidence was sufficient to prove that Mr Trump obstructed justice.

“Mueller, and the A.G. based on Mueller findings (and great intelligence), have already ruled No Collusion, No Obstruction,” Mr Trump tweeted. “These were crimes committed by Crooked Hillary, the DNC, Dirty Cops and others! INVESTIGATE THE INVESTIGATORS!”

William Barr
William Barr (Andrew Harnik/AP)

In his letter, Mr Barr noted that Mr Mueller’s team did not exonerate the president of obstruction of justice.

Democrats immediately called for Mr Mueller to testify and for his report to be released. Portions of the report being released by the Justice Department will be redacted to protect grand jury material, sensitive intelligence, matters that could affect ongoing investigations and damage to the privacy rights of third parties, the attorney general has said.

Mr Trump and his allies are also attacking the origins of the Russia investigation, portraying it as an effort by Democrats and career officials in the Justice Department who wanted to bring down a president.

“The Mueller Report, which was written by 18 Angry Democrats who also happen to be Trump Haters (and Clinton Supporters), should have focused on the people who SPIED on my 2016 Campaign, and others who fabricated the whole Russia Hoax. That is, never forget, the crime.” he tweeted.

His long-asserted accusation — though not supported by evidence — that his campaign was spied on was given new life last week when Mr Barr, testifying before Congress, said “spying did occur” in 2016.

He may have been referring to a surveillance warrant the FBI obtained in autumn 2016 to monitor the communications of former Trump campaign aide Carter Page, who has not been charged with any wrongdoing.

The warrant was obtained after Mr Page left the campaign and was renewed several times.

Critics of the Russia investigation have seized on the fact that the warrant application cited Democratic-funded opposition research, done by a former British spy, into the Trump campaign’s ties to Russia.

Mr Barr later softened his tone, adding: “I am not saying improper surveillance occurred.”