President Donald Trump and many of his aides engaged in a months-long effort to strong-arm the Ukrainian government into discrediting his political rivals, then worked extensively to cover up the evidence of their wrongdoing, according to a whistle-blower complaint released Thursday.

The document shows that a huge range of officials throughout the executive branch were aware of Trump’s pressure on Ukraine. Their reported efforts to keep the president’s behavior under wraps confirm that many of them also realized it was improper. The report also states that despite Trump’s insistence that he was not demanding a quid pro quo, Ukrainian officials understood him to be doing precisely that.

Not all of the complaint has been substantiated, though the inspector general for the Office of the Director of National Intelligence assessed it, conducted additional interviews, and found it credible. Much of the report’s value, however, comes in its careful and thorough collation of information that has long been public and acknowledged by the president or his aides.

The whistle-blower was not a direct witness to the events, but became aware of them from multiple officials as part of his or her work, suggesting that troubled aides brought their concerns to him or her.

“In the course of my official duties, I have received information from multiple U.S. Government officials that the President of the United States is using the power of his office to solicit interference from a foreign country in the 2020 U.S. election,” the whistle-blower writes. “This interference includes, among other things, pressuring a foreign country to investigate one of the President’s main domestic political rivals.”

The report adds, “I am also concerned that these actions pose risks to U.S. national security and undermine the U.S. Government’s efforts to deter and counter foreign interference in U.S. elections.”

Central to the complaint is the July 25 phone call between Trump and Ukrainian President Volodymyr Zelensky, a highly incriminating transcript of which the White House released on Wednesday. During that call, Trump discussed American aid to Ukraine while pressuring Zelensky to find a server supposedly related to the hacking of the Democratic National Convention during the 2016 presidential election, and asking him to investigate the Biden family’s business dealings in Ukraine.

“The White House officials who told me this information were deeply disturbed by what had transpired in the phone call,” the report states. “They told me that there was already a ‘discussion ongoing’ with White House lawyers about how to treat the call because of the likelihood, in the officials’ retelling, that they had witnessed the President abuse his office for personal gain.”

But as the complaint makes clear, this was not a one-off call. Instead, the Trump administration had been involved in a sweeping, sustained effort since at least spring 2019 to dig up dirt in Ukraine. Rudy Giuliani, Trump’s personal attorney, conducted a series of meetings with Ukrainian officials, seeking information to discredit Trump’s political rivals. This included then–Prosecutor General Yuri Lutsenko, who had made public claims of corruption against the Bidens.

In May, Vice President Mike Pence canceled a scheduled trip to Zelensky’s inauguration, and Energy Secretary Rick Perry went instead. The whistle-blower says it was “made clear” that Trump didn’t want to meet with Zelensky until he saw how the Ukrainian president “chose to act” in office: “Multiple U.S. officials told me that Ukrainian leadership was led to believe that a meeting or phone call between the President and President Zelensky would depend on whether Zelensky showed willingness to ‘play ball’ on the issues that had been publicly aired by Mr. Lutsenko and Mr. Giuliani.” In other words, Ukrainian officials understood themselves to be engaged in a quid pro quo even before the July 25 phone call.

The Trump administration also abruptly fired the ambassador to Ukraine, a respected career Foreign Service officer. In an interview with the Ukrainian press, Giuliani alleged that she had been conspiring against Trump.

After the July 25 phone call, at least two meetings were held with Ukrainian officials to follow up on the discussion. On July 26, Trump’s special envoy to Ukraine, Kurt Volker, and Ambassador to the European Union Gordon Sondland met in Kiev with Zelensky, where they offered advice on how to “navigate” Trump’s demands.

On August 2, Giuliani met with a Zelensky aide in Madrid, in what officials characterized as a “direct follow-up” to the call. The meetings spotlight the unusual and disturbing nature of Trump’s actions: He was at once using taxpayer resources of the federal government and enlisting his personal lawyer as part of the scheme to pressure Ukraine.

Trump has denied that he did anything wrong, calling the phone call “perfect” on Wednesday. But the report suggests that other federal officials were well aware that what Trump was doing was improper, and they tried to find ways to either mitigate it or cover it up.

In conversation with Giuliani, State Department officials, including Volker and Sondland, sought to “‘contain the damage’ to U.S. national security” of the lawyer’s actions, and advised the Ukrainian government on how to deal with conflicting messages from the U.S. government and from Giuliani, the whistle-blower alleges.

But various officials also tried to hide evidence of Trump’s improper behavior. White House officials were apparently horrified by the July 25 call, and sought to ensure that it was stifled. Contrary to standard procedure, the report alleges, they restricted access to records of the phone call, including the transcript. White House lawyers allegedly directed officials to remove the file from standard storage, and they placed it in a separate system for especially sensitive classified information. The whistle-blower says he or she was told this might be an abuse of the computer system, since the transcript did not relate to heavily classified intelligence matters.

There are many reasons the whistle-blower complaint is deeply damaging to the Trump White House, but one of the biggest is the sheer number of officials who were involved. According to the report, multiple officials in the White House, including national-security staffers and lawyers, were aware of both the pressure campaign against Ukraine and the efforts to cover it up. So were State Department staffers. That offers a wide range of potential witnesses for Democrats to call as they embark on an impeachment inquiry—and guarantees a long and messy investigation in the report’s wake.