As the impeachment hearings get more and more alarming for Donald Trump, with damning new evidence emerging every day, there appears to be increasing urgency in the parallel counteroffensives under way by the president’s team in an attempt to defend him.

There are attacks against the witnesses giving testimony by Trump and his supporters, including attempts to smear Lieutenant Colonel Alexander Vindman, Ukraine expert at the National Security Council who this week provided crucial testimony about Trump’s telephone call to Ukrainian president Volodymyr Zelensky. And there have been the extraordinary scenes of congress Republicans breaking into the proceedings and disrupting them.

At the same time, overshadowed by the publicity around the impeachment, is the ever-broadening investigation by William Barr, the attorney general, which the White House sees as a game-changer. An investigation which is seeking nothing less than to overturn the conclusion of the US intelligence services and special counsel Robert Mueller that Russia interfered in the last US presidential election.

This has now been designated a criminal investigation with power of subpoena and the possibility of prison sentences for those who have been allegedly involved in criminal actions, although exactly what these criminal actions entail remains unclear.

It may also seem odd that Trump, having repeatedly claimed that the Mueller report was a “complete and total exoneration” of him over Russiagate, is now going to such lengths to try and discredit it.

Trump impeachment: Who's who in the Ukraine scandal Show all 26 1 /26 Trump impeachment: Who's who in the Ukraine scandal Trump impeachment: Who's who in the Ukraine scandal Donald Trump Accused of abusing his office by pressing the Ukrainian president in a July phone call to help dig up dirt on Joe Biden, who may be his Democratic rival in the 2020 election. He also believes that Hillary Clinton’s deleted emails - a key factor in the 2016 election - may be in Ukraine, although it is not clear why. EPA Trump impeachment: Who's who in the Ukraine scandal The Whistleblower Believed to be a CIA agent who spent time at the White House, his complaint was largely based on second and third-hand accounts from worried White House staff. Although this is not unusual for such complaints, Trump and his supporters have seized on it to imply that his information is not reliable. Expected to give evidence to Congress voluntarily and in secret. Getty Trump impeachment: Who's who in the Ukraine scandal The Second Whistleblower The lawyer for the first intelligence whistleblower is also representing a second whistleblower regarding the President's actions. Attorney Mark Zaid said that he and other lawyers on his team are now representing the second person, who is said to work in the intelligence community and has first-hand knowledge that supports claims made by the first whistleblower and has spoken to the intelligence community's inspector general. The second whistleblower has not yet filed their own complaint, but does not need to to be considered an official whistleblower. Getty Trump impeachment: Who's who in the Ukraine scandal Rudy Giuliani Former mayor of New York, whose management of the aftermath of the September 11 attacks in 2001 won him worldwide praise. As Trump’s personal attorney he has been trying to find compromising material about the president’s enemies in Ukraine in what some have termed a “shadow” foreign policy. In a series of eccentric TV appearances he has claimed that the US state department asked him to get involved. Giuliani insists that he is fighting corruption on Trump’s behalf and has called himself a “hero”. AP Trump impeachment: Who's who in the Ukraine scandal Volodymyr Zelensky The newly elected Ukrainian president - a former comic actor best known for playing a man who becomes president by accident - is seen frantically agreeing with Trump in the partial transcript of their July phone call released by the White House. With a Russian-backed insurgency in the east of his country, and the Crimea region seized by Vladimir Putin in 2014, Zelensky will have been eager to please his American counterpart, who had suspended vital military aid before their phone conversation. He says there was no pressure on him from Trump to do him the “favour” he was asked for. Zelensky appeared at an awkward press conference with Trump in New York during the United Nations general assembly, looking particularly uncomfortable when the American suggested he take part in talks with Putin. AFP/Getty Trump impeachment: Who's who in the Ukraine scandal Mike Pence The vice-president was not on the controversial July call to the Ukrainian president but did get a read-out later. However, Trump announced that Pence had had “one or two” phone conversations of a similar nature, dragging him into the crisis. Pence himself denies any knowledge of any wrongdoing and has insisted that there is no issue with Trump’s actions. It has been speculated that Trump involved Pence as an insurance policy - if both are removed from power the presidency would go to Democratic House Speaker Nancy Pelosi, something no Republican would allow. AP Trump impeachment: Who's who in the Ukraine scandal Rick Perry Trump reportedly told a meeting of Republicans that he made the controversial call to the Ukrainian president at the urging of his own energy secretary, Rick Perry, and that he didn’t even want to. The president apparently said that Perry wanted him to talk about liquefied natural gas - although there is no mention of it in the partial transcript of the phone call released by the White House. It is thought that Perry will step down from his role at the end of the year. Getty Trump impeachment: Who's who in the Ukraine scandal Joe Biden The former vice-president is one of the frontrunners to win the Democratic nomination, which would make him Trump’s opponent in the 2020 election. Trump says that Biden pressured Ukraine to sack a prosecutor who was investigating an energy company that Biden’s son Hunter was on the board of, refusing to release US aid until this was done. However, pressure to fire the prosecutor came on a wide front from western countries. It is also believed that the investigation into the company, Burisma, had long been dormant. Reuters Trump impeachment: Who's who in the Ukraine scandal Hunter Biden Joe Biden’s son has been accused of corruption by the president because of his business dealings in Ukraine and China. However, Trump has yet to produce any evidence of corruption and Biden’s lawyer insists he has done nothing wrong. AP Trump impeachment: Who's who in the Ukraine scandal William Barr The attorney-general, who proved his loyalty to Trump with his handling of the Mueller report, was mentioned in the Ukraine call as someone president Volodymyr Zelensky should talk to about following up Trump’s preoccupations with the Biden’s and the Clinton emails. Nancy Pelosi has accused Barr of being part of a “cover-up of a cover-up”. AP Trump impeachment: Who's who in the Ukraine scandal Mike Pompeo The secretary of state initially implied he knew little about the Ukraine phone call - but it later emerged that he was listening in at the time. He has since suggested that asking foreign leaders for favours is simply how international politics works. Gordon Sondland testified that Pompeo was "in the loop" and knew what was happening in Ukraine. Pompeo has been criticised for not standing up for diplomats under his command when they were publicly criticised by the president. AFP via Getty Trump impeachment: Who's who in the Ukraine scandal Nancy Pelosi The Democratic Speaker of the House had long resisted calls from within her own party to back a formal impeachment process against the president, apparently fearing a backlash from voters. On September 24, amid reports of the Ukraine call and the day before the White House released a partial transcript of it, she relented and announced an inquiry, saying: “The president must be held accountable. No one is above the law.” Getty Trump impeachment: Who's who in the Ukraine scandal Adam Schiff Democratic chairman of the House intelligence committee, one of the three committees leading the inquiry. He was criticized by Republicans for giving what he called a “parody” of the Ukraine phone call during a hearing, with Trump and others saying he had been pretending that his damning characterisation was a verbatim reading of the phone call. He has also been criticised for claiming that his committee had had no contact with the whistleblower, only for it to emerge that the intelligence agent had contacted a staff member on the committee for guidance before filing the complaint. The Washington Post awarded Schiff a “four Pinocchios” rating, its worst rating for a dishonest statement. Reuters Trump impeachment: Who's who in the Ukraine scandal Lev Parnas and Igor Fruman Florida-based businessmen and Republican donors Lev Parnas (pictured with Rudy Giuliani) and Igor Fruman were arrested on suspicion of campaign finance violations at Dulles International Airport near Washington DC on 9 October. Separately the Associated Press has reported that they were both involved in efforts to replace the management of Ukraine's gas company, Naftogaz, with new bosses who would steer lucrative contracts towards companies controlled by Trump allies. There is no suggestion of any criminal activity in these efforts. Reuters Trump impeachment: Who's who in the Ukraine scandal William Taylor The most senior US diplomat in Ukraine and the former ambassador there. As one of the first two witnesses in the public impeachment hearings, Taylor dropped an early bombshell by revealing that one of his staff – later identified as diplomat David Holmes – overheard a phone conversation in which Donald Trump could be heard asking about “investigations” the very day after asking the Ukrainian president to investigate his political enemies. Taylor expressed his concern at reported plans to withhold US aid in return for political smears against Trump’s opponents, saying: “It's one thing to try to leverage a meeting in the White House. It's another thing, I thought, to leverage security assistance -- security assistance to a country at war, dependent on both the security assistance and the demonstration of support." Getty Images Trump impeachment: Who's who in the Ukraine scandal George Kent A state department official who appeared alongside William Taylor wearing a bow tie that was later mocked by the president. He accused Rudy Giuliani, Mr Trump’s personal lawyer, of leading a “campaign of lies” against Marie Yovanovitch, who was forced out of her job as US ambassador to Ukraine for apparently standing in the way of efforts to smear Democrats. Getty Images Trump impeachment: Who's who in the Ukraine scandal Marie Yovanovitch One of the most striking witnesses to give evidence at the public hearings, the former US ambassador to Ukraine received a rare round of applause as she left the committee room after testifying. Canadian-born Yovanovitch was attacked on Twitter by Donald Trump while she was actually testifying, giving Democrats the chance to ask her to respond. She said she found the attack “very intimidating”. Trump had already threatened her in his 25 July phone call to the Ukrainian president saying: “She’s going to go through some things.” Yovanovitch said she was “shocked, appalled and devastated” by the threat and by the way she was forced out of her job without explanation. REUTERS Trump impeachment: Who's who in the Ukraine scandal Alexander Vindman A decorated Iraq War veteran and an immigrant from the former Soviet Union, Lt Col Vindman began his evidence with an eye-catching statement about the freedoms America afforded him and his family to speak truth to power without fear of punishment. One of the few witnesses to have actually listened to Trump’s 25 July call with the Ukrainian president, he said he found the conversation so inappropriate that he was compelled to report it to the White House counsel. Trump later mocked him for wearing his military uniform and insisting on being addressed by his rank. Getty Images Trump impeachment: Who's who in the Ukraine scandal Jennifer Williams A state department official acting as a Russia expert for vice-president Mike Pence, Ms Williams also listened in on the 25 July phone call. She testified that she found it “unusual” because it focused on domestic politics in terms of Trump asking a foreign leader to investigate his political opponents. Getty Images Trump impeachment: Who's who in the Ukraine scandal Kurt Volker The former special envoy to Ukraine was one of the few people giving evidence who was on the Republican witness list although what he had to say may not have been too helpful to their cause. He dismissed the idea that Joe Biden had done anything corrupt, a theory spun without evidence by the president and his allies. He said that he thought the US should be supporting Ukraine’s reforms and that the scheme to find dirt on Democrats did not serve the national interest. Getty Images Trump impeachment: Who's who in the Ukraine scandal Tim Morrison An expert on the National Security Council and another witness on the Republican list. He testified that he did not think the president had done anything illegal but admitted that he feared it would create a political storm if it became public. He said he believed the moving the record of the controversial 25 July phone call to a top security server had been an innocent mistake. Getty Images Trump impeachment: Who's who in the Ukraine scandal Gordon Sondland In explosive testimony, one of the men at the centre of the scandal got right to the point in his opening testimony: “Was there a quid pro quo? Yes,” said the US ambassador to the EU who was a prime mover in efforts in Ukraine to link the release of military aid with investigations into the president’s political opponents. He said that everyone knew what was going on, implicating vice-president Mike Pence and secretary of state Mike Pompeo. The effect of his evidence is perhaps best illustrated by the reaction of Mr Trump who went from calling Sondland a “great American” a few weeks earlier to claiming that he barely knew him. AP Trump impeachment: Who's who in the Ukraine scandal Laura Cooper A Pentagon official, Cooper said Ukrainian officials knew that US aid was being withheld before it became public knowledge in August – undermining a Republican argument that there can’t have been a quid pro quo between aid and investigations if the Ukrainians didn’t know that aid was being withheld. Getty Images Trump impeachment: Who's who in the Ukraine scandal David Hale The third most senior official at the state department. Hale testified about the treatment of Marie Yovanovitch and the smear campaign that culminated in her being recalled from her posting as US ambassador to Ukraine. He said: “I believe that she should have been able to stay at post and continue to do the outstanding work.” EPA Trump impeachment: Who's who in the Ukraine scandal Fiona Hill Arguably the most confident and self-possessed of the witnesses in the public hearings phase, the Durham-born former NSC Russia expert began by warning Republicans not to keep repeating Kremlin-backed conspiracy theories. In a distinctive northeastern English accent, Dr Hill went on to describe how she had argued with Gordon Sondland about his interference in Ukraine matters until she realised that while she and her colleagues were focused on national security, Sondland was “being involved in a domestic political errand”. She said: “I did say to him, ‘Ambassador Sondland, Gordon, this is going to blow up’. And here we are.” AP Trump impeachment: Who's who in the Ukraine scandal David Holmes The Ukraine-based diplomat described being in a restaurant in Kiev with Gordon Sondland while the latter phoned Donald Trump. Holmes said he could hear the president on the other end of the line – because his voice was so “loud and distinctive” and because Sondland had to hold the phone away from his ear – asking about the “investigations” and whether the Ukrainian president would cooperate. REUTERS

Ukraine is a common factor in both the impeachment hearings and the Barr investigation. The House is looking at claims that Trump withheld military aid to Kiev to force the Zelensky government to reopen investigations into unproven allegations, with Trump’s personal lawyer Rudy Giuliani playing a leading part in this campaign.

The attorney general is focusing on the theory, aired on far-right conspiracy sites, and raised by Trump and Giuliani, that Ukraine framed Vladimir Putin over the US election in a complex triple-cross operation by impersonating Russian hackers.

Trump and Barr have also been asking other foreign governments for help in investigating the FBI, CIA and Mueller investigators. The US president has called on the Australian prime minister Scott Morrison for assistance, while the attorney general has been on similar missions to the UK and Italy.

And the information being requested has left allies astonished. One British official with knowledge of Barr’s wish list presented to London commented that “it is like nothing we have come across before, they are basically asking, in quite robust terms, for help in doing a hatchet job on their own intelligence services”.

The UK, in particular, has been viewed by Trump followers, especially far-right conspiracy theorists, as a deep source of woes for the president.

The claims that Trump was the Muscovian candidate for the White House effectively began to take shape after a meeting in May 2016 between Alexander Downer, the then Australian high commissioner in London, and George Papadopoulos, a foreign policy advisor for the Trump campaign, at a bar, the Kensington Wine Rooms in west London.

Downer passed on what he had heard to Australian officials, who shared it with the ASIO (Australian Security Intelligence Organisation), who in turn got in touch with the FBI. They then officially launched their investigation the following month.

Downer continues to live in London. He is the chair of trustees of the think tank Policy Exchange, and executive chairman of the International School of Government at King’s College, London, as well as holding positions in various businesses.

Then there is the dossier produced by Christopher Steele, a former MI6 officer, on allegations that the Kremlin had compromising material, kompromat, on Trump. The report was passed on to FBI director James Comey, who was subsequently fired by Trump, in December 2017 by Senator John McCain.

The Italian connection relates to Joseph Mifsud, a Maltese academic who had provided information to Papadopoulos about claims of Russian involvement.

Mifsud, who was affiliated to Link University in Rome, which has connections internationally with the security sector, has not been seen in public since November 2017. The Mueller report presented the academic as a possible Russian asset, but Trump supporters hold that he may have been working for western intelligence services. The fact Steele’s first meeting with the FBI took place in Rome has reinforced the tale of dark machinations.

Two weeks ago Giuseppe Conte, the Italian prime minister, revealed that Barr had visited his country twice in the previous two months, alongside John Durham, the Connecticut attorney he had appointed to lead his investigation, and had pressed for information about the activities of the US intelligence services.

Rudy Giuliani reads texts suggesting Kurt Volker and the state department were 'all over him' to get involved with Ukraine

But it is Christopher Steele who is the particular bête noire of Trump followers and they blame his report for starting the FBI investigation into Russian interference.

The House Intelligence Committee, then under Republican control, decided however that it was the Papadopoulous information which was the trigger. The same conclusion was separately drawn by the staff of the then Republican chair of the committee, Devin Nunes.

Trump loyalist Nunes, who his hometown newspaper in California has called “Trump’s stooge”, had to step down at one stage over allegations that he was colluding with the White House during the House investigation. He had, in the past, tried to carry out his own “Barr-Lite” version of investigating the investigators.

In August 2016, two staffers from the Nunes-run House Intelligence Committee suddenly turned up from the US 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 come with the aim, it was suspected, of intimidating Steele. Nothing discernible appears to have resulted from their trip.

Julian Assange is another UK connection in the narrative. A year before Trump won the election Assange, holed up in the Ecuadorian embassy in London, had told his colleagues in WikiLeaks, the organisation he founded, in a Twitter group chat that Hillary Clinton was a “bright, well connected, sadistic sociopath” and it would be better if the Republicans could seize power. WikiLeaks subsequently disseminated emails stolen, as multiple investigations have established, from Democratic Party computers by Russian hackers. Assange is in prison in the UK facing extradition to the US for alleged espionage offences.

A number of Trump associates have been under investigation by Mueller for their links to Assange. These include Roger Stone, a long-term and close advisor to the US president who was arrested last January. He goes on trial next week on charges of lying to congress, obstruction and witness tampering.

There have also been claims that Trump supporters not known to have been investigated by the special counsel had held clandestine meetings with Assange.

Glenn Simpson, whose Washington-based investigations firm hired Steele to compile the Trump report, told a US congressional inquiry in January that Nigel Farage was a more frequent visitor to Assange than was known and that he had passed data on to Assange on “a thumb drive”.

Farage had long boasted of his closeness to Trump. On Thursday, speaking to Farage on his LBC show, the US president advised Boris Johnson to form an alliance with the Brexit Party leader to fight the coming UK general election.

The former Ukip leader visited Assange at the embassy in 2017 after returning from a trip to the US. The news of the visit broke after a member of the public saw him go into the building.

Farage had denied claims of any collusion, but refused to tell a number of news organisations what he had discussed with Assange. He said to me when I asked him about the matter: “I met Julian Assange just once. I went there in a journalistic capacity because like you I wanted to find out about the emails, no real answer was forthcoming. It is nonsense to say that I had met him secretly. Do you think one of the best known faces in the country can go into the embassy without people noticing?”

Ukraine’s president Volodymyr Zelenskiy greets Donald Trump during September’s UN General Assembly in New York (Reuters)

The Trump followers’ counternarrative is that US intelligence and security services had deliberately, and wrongly, concluded that the Russians were behind the hacking. The real culprit, they allege, was a private company, Crowdstrike, which is run with an anti-Russian agenda.

Crowdstrike was a security firm hired by the Democratic Party to investigate the data breach and was the first of many, including western intelligence agencies, to find that Russia’s military intelligence agency, the GRU, had carried it out.

According to the conspiracy theories, Crowdstrike has a Ukrainian base, and its founder Dmitri Alperovitch is a Ukrainian who set up Putin in revenge for invading his homeland. But Alperovitch, in real life, is of Russian extraction and is a US citizen whose family came to America in the Soviet era. Crowdstrike is based not in Kiev, but California.

Every aspect of the Crowdstrike conspiracy tale has been disproved. But this has not stopped Trump from demanding that Zelensky looks into it, albeit in a somewhat incoherent manner, in the now infamous 25 July call to the Ukrainian president.

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“I would like you to find out what happened with this whole situation with Ukraine, they say Crowdstrike. I guess you have one of your wealthy people. The server, they say Ukraine has it,” said the US president, according to notes of the conversation, released by the White House. In another part of the call Trump tells Zelensky “they say” Mueller “started with Ukraine”.