WASHINGTON — The whistleblower at the center of Congress’ impeachment inquiry alleged that President Donald Trump abused the power of his office to “solicit interference from a foreign country” in next year’s U.S. election. The White House then tried to “lock down” the information to cover it up, the official’s complaint says.

The 9-page document released Thursday provides many new details about the summertime phone call in which Trump encouraged the president of Ukraine to help investigate political rival Joe Biden. It alleges a concerted White House effort to suppress the transcript of the call and describes a shadow campaign of diplomacy by the president’s personal lawyer Rudy Giuliani that unnerved some senior Trump administration officials.

“In the days following the phone call, I learned from multiple U.S. officials that senior White House officials had intervened to ‘lock down’ all the records of the phone call, especially the official word-for-word transcript of the call that was produced as is customary by the White House situation room,” the complaint says.

The previously secret document, with its detail and clear narrative, will likely accelerate the impeachment process and put more pressure on Trump to rebut its core contentions and on his fellow Republicans to defend him or not. It also provides a road map for Democrats to seek corroborating witnesses and evidence, which will complicate the president’s efforts to characterize the findings as those of a lone partisan out to undermine him.

Trump threatened the person who gave information to the whistleblower as he spoke at a private event in New York with staff from the U.S. mission to the United Nations.

“I want to know who’s the person, who’s the person who gave the whistleblower the information? Because that’s close to a spy,” Trump said. “You know what we used to do in the old days when we were smart? Right? The spies and treason, we used to handle it a little differently than we do now.”