Moments after Donald Trump ended his phone call with Ukraine's president on 25 July, an unsettled national security aide rushed to the office of White House lawyer John Eisenberg.

Army Lieutenant Colonel Alexander Vindman, the top Ukraine adviser at the White House, had been listening to the call and was disturbed by the pressure the US president had applied to his Ukrainian counterpart Volodymyr Zelensky to investigate his political rivals, according to people familiar with Mr Vindman's testimony to lawmakers this week.

They told Mr Eisenberg, the White House's legal adviser on national security issues, that what the president did was wrong.

Scribbling notes on a yellow legal pad, Mr Eisenberg proposed a step that other officials have said is at odds with long-standing White House protocol: moving a transcript of the call to a highly classified server and restricting access to it, according to two people familiar with Mr Vindman's account.

The details of how the White House clamped down on information about the controversial call comes as the House impeachment inquiry turns its focus to the role of Mr Eisenberg, who has served as deputy White House counsel since the start of Mr Trump's administration.

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

House impeachment investigators announced on Wednesday they have asked Mr Eisenberg and a fellow White House lawyer, Mike Ellis, to testify on Monday.

Mr Bolton has also been asked to testify next week.

Mr Vindman's account marks the first known instance in which a witness before the impeachment inquiry has provided a firsthand account linking Mr Eisenberg to the decision to move the problematic transcript to a highly classified server.

M Eisenberg did not respond to requests for comment. A White House spokesman declined to discuss Mr Eisenberg's role in handling the 25 July transcript or how he addressed the concerns he heard from staff.

"Consistent with the practices of past administrations from both parties, we will not discuss the internal deliberations of the White House Counsel's Office," said deputy White House press secretary Hogan Gidley.

Mr Eisenberg, who worked in the Washington office of the law firm Kirkland & Ellis before joining the Trump administration, also served in the Justice Department during the George W Bush administration.

He has been deputy White House counsel overseeing national security issues since Mr Trump's inauguration, serving under both former White House counsel Donald McGahn and his successor, Pat Cipollone.

By the time Mr Vindman came to him in late July, he was already familiar with concerns among White House officials about the administration's attempts to pressure Ukraine for political purposes, as The Washington Post previously reported.

Three weeks earlier, Mr Vindman and another senior official had gone to him after a contentious 10 July meeting in which they said Gordon Sondland, the US ambassador to the EU, had pushed two Ukrainian officials to investigate the US president's political rivals, including former vice president Joe Biden, whose son Hunter served on the board of Burisma, a Ukrainian gas company.

Mr Sondland's attorney, Robert Luskin, said on Wednesday that his client did not mention the Bidens in the 10 July meeting or any other discussions about Ukraine policy.

He said: "Ambassador Sondland has nothing to add to his prepared testimony in which he makes clear that he did not then or on any other occasion mention any Biden by name and did not then know that Burisma was linked to Biden."

That day, two officials representing the newly elected Ukrainian president had come to the White House hoping to shore up relations with the Trump administration.

Instead, the visitors found themselves caught in a showdown between top White House officials.

The two Ukrainian visitors - Andriy Yermak, a top Zelensky adviser, and Oleksandr Danyliuk, the head of Ukraine's national security and defence council - were first escorted to Mr Bolton's office, where they met with Mr Vindman, Mr Sondland, White House Russia adviser Fiona Hill and Kurt Volker, the State Department's special envoy to Ukraine.

Grandma Winnie calls for Donald Trump's impeachment for her birthday

As the group discussed the United States' desire to see Kiev crack down on corruption, Mr Sondland turned the conversation away from ongoing corruption probes to pursuing specific investigations that were important to the US president, according to testimony from Ms Hill and Mr Vindman.

Mr Bolton was so alarmed by the comments that he cut the meeting short, according to people familiar with the testimony.

The US ambassador to the EU then asked the Ukrainians to accompany him to a previously scheduled debriefing in the Ward Room, a basement conference area used by the national security team.

During that meeting, Mr Sondland "emphasised the importance that Ukraine deliver the investigations into the 2016 election, the Bidens, and Burisma", a reference to a gas company that tapped Mr Biden's son Hunter to be on its board, according to Mr Vindman's opening statement to lawmakers.

The National Security Council expert ​objected, telling the ambassador that the request was "totally inappropriate", according to a person familiar with his testimony.

As tensions mounted, Mr Sondland asked the two Ukrainian officials if they would like to step out of the meeting temporarily.

Ms Hill, whom Mr Bolton had instructed to monitor Mr Sondland, had just entered the Ward Room. She immediately echoed Mr Vindman's objections that the request was counter to national security goals, according to her testimony.

"She was very emotional," one person who heard Mr Vindman's account of the meeting recalled, adding that Ms Hill raised her voice and strongly objected.

Mr Vindman and Ms Hill complained directly to Mr Eisenberg about the episode, according to his testimony and people familiar with their actions.

It is unclear whether the White House lawyer took any steps in response.

Weeks later, Mr Vindman grew even more alarmed as he sat in the Situation Room listening to Mr Trump speak with Mr Zelensky.

Among the officials present were Mr Morrison, who had just replaced Ms Hill as the senior Russia adviser at the White House, and retired Lieutenant General Keith Kellogg, Mike Pence's national security adviser.

"I would like you to do us a favour," the US president told his Ukrainian counterpart, then asked him to look into the debunked conspiracy theory that a Democratic National Committee server was transported to Ukraine after it was hacked in 2016, according to a rough transcript released by the White House.

Mr Trump also asked Mr Zelensky to pursue an investigation into Mr Biden and his son, the transcript shows.

Stunned, Mr Vindman looked up and made eye contact with Mr Morrison, the person said.

In his statement to lawmakers, Mr Vindman said he "did not think it was proper to demand that a foreign government investigate a US citizen, and I was worried about the implications for the US government's support of Ukraine".

After the call, he hurried to Mr Eisenberg's door, bringing with him his twin brother, Yevgeny, an ethics attorney on the National Security Council.

Mr Ellis, a deputy legal adviser to the National Security Council, also joined the discussion, the person said.

Mr Vindman read out loud notes he took of the president's call. He said Mr Eisenberg then suggested that the National Security Council move records of the call to a separate, highly classified computer system.

The White House lawyer later directed the transcript's removal to a system known as NICE, for NSC Intelligence Collaboration Environment, which is normally reserved for code word-level intelligence programmes and top-secret sources and methods, according to an administration official.

Former Trump national security officials said it was unheard of to store presidential calls with foreign leaders on the NICE system but that the White House lawyer had moved at least one other transcript of a Trump phone call there.

On 25 September, under mounting political pressure, the White House released the rough transcript of the Zelensky call. Mr Trump has declared it a "perfect call" and proof that he has not done anything wrong.

In his testimony, Mr Vindman recalled that on the call, M Zelensky raised Burisma by name in response to Mr Trump's request that the Ukrainians look into the Bidens - a detail not included in the transcript released by the White House.