United States (U.S) top Democrats accused the White House, on Thursday, of engaging in a “cover up” by trying to suppress a record of a phone call in which President Donald Trump urged the leader of Ukraine to investigate former vice president Joe Biden.

“This is a cover up,” Nancy Pelosi, the speaker of the House of Representatives, told reporters, as she laid out part of her case for impeaching the president for abuse of power.

A whistleblower alleged White House lawyers ordered the record of the call be moved to a separate restricted electronic system, which Pelosi said “the White House used to hide information of a political nature.”

Pelosi alleged the move was an attempt by the White House to “hide information of a political nature.”

There was no immediate reaction from Biden, the frontrunner for the 2020 Democratic presidential nomination, to the release of the whistleblower’s complaint but other Democratic candidates accused the White House of a “cover up.”

“Donald Trump solicited foreign interference in our elections from the Oval Office,” Massachusetts Senator Elizabeth Warren said on Twitter.

“He attempted to cover up his actions. And his appointees intervened, against the law, to attempt to suppress this whistleblower complaint.”

Vermont Senator Bernie Sanders said the whistleblower complaint “is only the tip of an iceberg of corrupt, illegal and immoral behavior by this president.”

“What the House must do is thoroughly investigate Trump’s cover-up of this call and his other attempts to use government resources to help his re-election campaign,” Sanders said in a statement.

Julian Castro, another 2020 Democratic candidate, also accused the White House of a cover up.

“The #WhistleblowerComplaint has exposed a criminal effort to extort political dirtywork from a foreign government, and a massive cover-up orchestrated by the White House,” Castro said.

During the call, Trump repeatedly asked Zelensky to conduct an investigation into Biden and his son, Hunter, who served on the board of a Ukrainian gas company.

Revelations about the call prompted the House of Representatives to launch an impeachment inquiry seeking to remove the president for abuse of power.

In the complaint, the whistleblower said some White House officials were “deeply disturbed by what had transpired in the phone call” because of the likelihood “they had witnessed the president abuse his office for personal gain.”

The whistleblower alleged that senior White House officials had “intervened to ‘lock down’ all records of the phone call,” including the transcript, which was released by the White House on Wednesday.

“White House officials told me that they were ‘directed’ by White House lawyers to remove the electronic transcript from the computer system in which such transcripts are typically stored,” the complaint says.

“Instead, the transcript was loaded into a separate electronic system that is otherwise used to store and handle classified information of an especially sensitive nature,” it adds. (AFP)