Former Trump White House official Peter Navarro contended that Congress pushing him to testify violated the Constitution’s separation of powers.

“The irony is that the Department of Justice itself has maintained a policy for more than 50 years that says that senior advisers like me absolutely cannot be compelled to testify before Congress,” Mr. Navarro told Fox’s Sean Hannity on Friday.

He continued, “Why? Because it violates the constitutional separation of powers and interferes with the ability of executive privilege to provide effective presidential decision-making.”

Mr. Navarro’s ire comes after he was sentenced to four months in prison on Thursday for failing to comply with a congressional subpoena related to the Jan. 6, 2021, protest at the U.S. Capitol.

His sentencing this week came after he was the second former official in the Trump administration convicted of skirting a congressional subpoena. Steve Bannon was also hit with a four-month sentence but has remained free pending his appeal.

The subpoena that Mr. Navarro defied requested that he provide documents and appear for a deposition for the now-defunct House Jan. 6 Select Committee.

Mr. Navarro has vowed to appeal the verdict, arguing that he couldn’t cooperate with the committee because former President Donald Trump invoked executive privilege.

The former adviser believes he has a “great case” that could go all the way to the Supreme Court. He told Mr. Hannity that his sentencing was a result of prosecutors trying to go after Mr. Trump.

“If anybody thinks they’re not trying to put Donald Trump in prison for 700 years, they just need to look at what they did to me [Thursday],” he said. “They’re not messing around.”

• Alex Miller can be reached at amiller@washingtontimes.com.