Special counsel Robert Mueller is the ultimate target in the release of a doctored version of a classified House Intelligence Committee memo by the White House. And the dossier produced by former British intelligence officer Christopher Steele is very much in the centre of this attempt to scupper the investigation into Donald Trump’s Russian connections.

As the inquiry into whether Donald Trump was the Muscovite Candidate in the US presidential election continues to make progress, with Mueller’s team starting to look at murky business affairs as well as other Kremlin links, the President’s supporters are increasingly desperate in their efforts to halt it in its tracks.

The narrative being put forward in the three and half page memo, compiled by Republicans in the House Committee, is that a group of politically motivated Justice Department and FBI officials started a campaign to sabotage the Trump presidency. That they used the material in former MI6 spy Steele’s report to obtain a wiretap order against Carter Page, a Trump campaign official with links to powerful figures in Moscow. And that in doing so they failed to disclose to the judge issuing the order that Steele’s research has been part-funded by the Democrats.

It should be pointed out that the Democrats in the House Committee have accused the Republicans, led by chairman Devin Nunes, of altering the content of the memo the Committee had agreed on. The Republicans admit doing so, but claim that the changes made were minor. The FBI, however, complained strongly that there are “material omissions of fact that fundamentally impact on the memo’s accuracy”. The Republican-dominated committee voted down a Democrat proposal that their rebuttal, pointing out the inaccuracies of the Republican memo, should also be made public.

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To put this in context, what became the Steele report was, in fact, originally commissioned by Republican opponents of Trump during the race for the party nomination. They hired the Washington-based firm Fusion GPS, which in turn brought in Steele because of his knowledge of Russia acquired while working for British intelligence. The Republican clients had no more need for the information after Trump won the candidacy and the Democrats briefly took over the commission. They too stopped after Trump’s election victory, at which point Steele continued working without pay for a while so worried was he by what was being discovered. The FBI had been receiving material from Steele’s research for a while: FBI Director James Comey – subsequently fired by Trump – was handed the report by the Republican Senator John McCain, who had obtained it from London.

The Justice Department has pointed out that the Steele report was not the only material presented to the judge to obtain the FISA (Foreign Intelligence Surveillance Act) order. And that it is also the case that the allegations made in the report have been independently verified by US intelligence. The Department said in a statement: “The FBI takes seriously its obligations to the FISA Court and its compliance with procedures overseen by career professionals in the Department of Justice and the FBI. We are committed to working with the appropriate oversight entities to ensure the continuing integrity of the FISA process.”

The White House wants to release the Republican memo as it will undoubtedly aid Trump’s tale of being a victim of a mythical “Deep State”. Nunes, whom his hometown newspaper in California has called “Trump’s stooge”, had refused to answer whether his staff had colluded with the White House on this. When questioned, White House spokeswoman Sarah Huckabee Sanders said she could not rule out the possibility of collusion, saying: “I just don’t know the answer.”

This has been the latest, and the most high-profile, of Nunes’ attempts to save Trump. He has had to temporarily step down in the past as the chairman of the House Committee after being exposed over secret contacts with the White House over the House’s Russia inquiry. And this is not the first time he had tried to use Christopher Steele to undermine the three investigations into the matter.

In August last year, two staffers from the House Intelligence Committee suddenly turned up at the London office of Steele’s company, Orbis. Not finding him there, they went to the office of his lawyer and demanded to see him. The timing of the visit was of importance. Mueller and the Senate Intelligence Committee, carrying out separate Russia investigations, were making progress in their attempts to speak to the former MI6 officer. The two men had been sent by Republican members of the House Committee with the aim, it was suspected, of intimidating Steele.

If the ultimate goal of the memo is to shut down the Mueller investigation, the immediate target is Deputy Attorney General Rod Rosenstein, the only official who can sack Mueller – and then only if he can prove that the special counsel has been guilty of misconduct.

Rosenstein has resisted pressure from Trump and his supporters to turn against Mueller, incurring their wrath. Trump has repeatedly railed against Rosenstein. Even last July he was annoyed that “Rosenstein is from Baltimore: there are very few Republicans from Baltimore, if any, he is a Democrat”. Rosenstein, it has been pointed out, is neither from Baltimore nor a Democrat. But Trump saw him as threat and, as the Mueller investigation grew in scope and success, it became increasingly imperative, it seems, to get rid of him.

Rosenstein has been repeatedly attacked by Trump’s fellow travellers. Now they are implicating the Deputy Attorney General in the Carter Page FISA because, they say, he agreed to a FBI request to renew the Page surveillance. Fox News host Sean Hannity, who often acts as Trump’s mouthpiece, declared that the Nunes memo showed “beyond any shadow of a doubt that the special counsel, Robert Mueller, and his band of Democratic witch hunters never should have been appointed and they need to be disbanded immediately… Did Rosenstein sign off on extension of this FISA warrant? I’m very interested about Rod Rosenstein in all of this.” Rosenstein, declared Hannity, should be fired.

Trump is said to have claimed that what comes out in the memo will give him the ammunition to fire Rosenstein. This, of course, would allow installing a replacement who may be more amenable to obey orders and, when the time comes, either hamstring Mueller or find a reason to fire him.

The Mueller investigation has made good progress. Two senior members of the Trump team, former campaign manager Paul Manafort and former national security advisor Lieutenant General Michael Flynn, have been arrested and charged along with one who was more junior, George Papadopoulos, who is regarded as an important link in the alleged conspiracy. The activities of Trump’s son, Donald Trump Jr, and his son-in-law, Jared Kushner, are under intense scrutiny from Mueller’s investigators and a false alibi Trump allegedly had a hand in concocting about a meeting between Trump Jr, Kushner, Manafort and a Russian lawyer, it has been revealed, is now a focus of attention.