WASHINGTON, D.C. — Acting Attorney General Matthew Whitaker told Congress Friday that he has not interfered with the special counsel’s investigation into Russia’s interference in the 2016 election and has not discussed the probe with President Donald Trump or other senior White House officials.

The testimony came early in a contentious House Judiciary Committee hearing led by Democrats, who sought to press the nation’s top law enforcement official about special counsel Robert S. Mueller III’s inquiry.

They are also expected to grill Whitaker about his controversial appointment last November, his relationship with Trump and his ties to an invention promotion company that was shut down by federal regulators who said it scammed consumers.

Whitaker is the first top Trump administration official to testify before Congress since Democrats won control of the House in the November midterm elections.

The hearing came a day after the chairman, Democratic Rep. Jerrold Nadler of New York, and Whitaker sparred over Nadler’s threat to issue a subpoena to compel his appearance to answer questions. In the end, Nadler backed down and Whitaker agreed to appear.

“At no time has the White House asked for nor have I provided any promises or commitments concerning the special counsel investigation or any other investigation,” Whitaker said in his opening remarks.

During his tenure, he added, the department has “complied with special counsel regulations and there has been no change in how the department has worked with the special counsel’s office.”

Under questioning by Nadler, Whitaker proved combative and sought to dodge questions about his conversations with Trump and his top advisers, citing long-standing policy against disclosing details of such discussions.

However, he said, “I have not spoken to the president about the special counsel’s investigation.”

He also testified he had taken no actions related to the probe. “There’s been no event, no decision that has required me to take any action, and I’ve not interfered in any way with the special counsel’s investigation,” he said.

He said he was briefed beforehand about the indictment last month of Roger Stone, an informal adviser to Trump and a longtime Republican operative who helped launch the president’s political career.

Stone was arrested before dawn Jan. 25 on a federal indictment that outlined efforts by Trump’s 2016 campaign to seek Democratic Party emails hacked by Russia.

Nadler said the hearing was crucial for lawmakers to get answers to questions about Whitaker’s role at the Department of Justice and his appointment. The chairman said in his opening statement that the acting attorney general’s “reluctance to answer questions about these communications as a deeply troubling sign.”

“When our members ask you if you conveyed sensitive information to the president, or ignored ethics advice at the direction of the president, or worked with the White House to orchestrate the firing of your predecessor, the answer should be ‘no,’” Nadler added.

During a combative back-and-forth with Whitaker, Nadler grew frustrated and announced his intention to recall Whitaker for a deposition, saying he expected Whitaker to then provide “clean” answers or to properly assert executive privilege.

Rep. Doug Collins of Georgia, the committee’s ranking Republican, said the hearing was “nothing more than a character assassination” and an attempt to “get at the president.” He suggested that the hearing was a waste of time because Whitaker likely only has a few more days on the job.

The Senate Judiciary Committee voted Thursday to support William P. Barr, Trump’s pick for attorney general, and the Republican-led Senate is expected to confirm him in coming weeks.

Whitaker took over from Attorney General Jeff Sessions on Nov. 7, the day after the midterm election, when Trump successfully sought the resignation of his top law enforcement official.

Trump soured on Sessions after the attorney general recused himself from the Russia investigation in early 2017, and the president frequently bashed the former senator on Twitter and in interviews.

Whitaker had served for a year as Sessions’ chief of staff and built a rapport with Trump.

Before joining the department, Whitaker had publicly criticized special counsel Robert S. Mueller III’s investigation in columns and in TV interviews.

As acting attorney general, he refused to recuse himself from supervising Mueller’s probe despite the advice of a career Justice Department ethics official who was concerned his past comments created the appearance of a conflict of interest, department officials said.

After Sessions recused himself from the federal investigation, its supervision fell to Deputy Attorney General Rod Rosenstein. In May 2017, he appointed Mueller and he continues to oversee the day-to-day operations of the investigation. Rosenstein is expected to step down in coming months.

In a news conference last month, Whitaker said he had been “fully briefed” on the Mueller investigation and that it was nearing a conclusion.

The House hearing nearly derailed on Thursday when Democrats on the panel voted to authorize Nadler to issue a subpoena to compel Whitaker to appear and answer questions.

Whitaker, who had agreed to testify voluntarily, responded by saying he would not attend the hearing unless Nadler promised he would not issue such a subpoena.

In a letter to Whitaker, Nadler withdrew the subpoena threat after the acting attorney agreed to attend the hearing.

The Justice Department issued a statement Thursday night that Nadler had “made the commitment that we requested” and would attend.