A Democrat on the House Intelligence Committee called for the House to begin impeaching President Trump by the end of the week if a whistleblower complaint against Trump is withheld from Congress.

House Speaker Nancy Pelosi gave the administration until Thursday to hand over the complaint, the same day acting Director of National Intelligence Joseph Maguire testifies to the House Intelligence Committee.

“She gave him a deadline of Thursday. If he’s not forthcoming, I think we should start impeachment on Friday before we leave town,” Texas Rep. Joaquin Castro told NPR on Monday.

Maguire has so far refused to release the complaint to congressional committees despite the House Intelligence Committee issuing a subpoena for it.

The whistleblower, who has not been identified publicly, submitted the complaint in August to the inspector general for the Office of the Director of National Intelligence that is related to a phone call between Trump and Ukrainian President Volodymyr Zelensky. Trump reportedly urged Zelensky eight times to collaborate with his personal lawyer, Rudy Giuliani, on an investigation into Hunter Biden, the son of Trump’s potential 2020 rival Joe Biden.

Hunter Biden was employed by Ukrainian natural gas company Burisma Holdings as a board member from 2014 until shortly before his father announced his 2020 presidential candidacy. As vice president, the elder Biden threatened to withhold $1 billion in U.S. loan guarantees if Ukraine did not fire its top prosecutor, who had been accused of corruption and had been investigating the oligarch who owned the energy company, raising concerns about a possible conflict of interest.

Giuliani met with top Ukrainian officials in June and August about a potential investigation into the matter.

Trump acknowledged to reporters on Sunday that he did discuss Biden with Ukraine’s president, but he defended the call as nothing out of the ordinary.

“The conversation I had was largely congratulatory, with largely corruption, all of the corruption taking place and largely the fact that we don’t want our people like Vice President Biden and his son creating to the corruption already in the Ukraine,” Trump said.

Castro said Trump’s comments likely show he was pushing the Ukrainian president to open an investigation into the Bidens.

“If in fact, he was pressuring the Ukrainian president to open an investigation on the former vice president, Vice President Biden, that’s an incredible abuse of power. A sitting president trying to basically force another president of another country to go after a political rival that by itself … is worthy of impeachment,” Castro said.

“I would point out that raising the issue eight times personally is pressure by itself because for the Ukraine, the United States is a lifeblood for them. The United States is critical in their protection against Russia. A U.S. president, eight times making this request about a political rival — that by itself is pressure.”